diff options
Diffstat (limited to 'security/keys')
24 files changed, 3047 insertions, 1644 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig new file mode 100644 index 00000000000..a4f3f8c48d6 --- /dev/null +++ b/security/keys/Kconfig @@ -0,0 +1,100 @@ +# +# Key management configuration +# + +config KEYS + bool "Enable access key retention support" + select ASSOCIATIVE_ARRAY + help + This option provides support for retaining authentication tokens and + access keys in the kernel. + + It also includes provision of methods by which such keys might be + associated with a process so that network filesystems, encryption + support and the like can find them. + + Furthermore, a special type of key is available that acts as keyring: + a searchable sequence of keys. Each process is equipped with access + to five standard keyrings: UID-specific, GID-specific, session, + process and thread. + + If you are unsure as to whether this is required, answer N. + +config PERSISTENT_KEYRINGS + bool "Enable register of persistent per-UID keyrings" + depends on KEYS + help + This option provides a register of persistent per-UID keyrings, + primarily aimed at Kerberos key storage. The keyrings are persistent + in the sense that they stay around after all processes of that UID + have exited, not that they survive the machine being rebooted. + + A particular keyring may be accessed by either the user whose keyring + it is or by a process with administrative privileges. The active + LSMs gets to rule on which admin-level processes get to access the + cache. + + Keyrings are created and added into the register upon demand and get + removed if they expire (a default timeout is set upon creation). + +config BIG_KEYS + bool "Large payload keys" + depends on KEYS + depends on TMPFS + help + This option provides support for holding large keys within the kernel + (for example Kerberos ticket caches). The data may be stored out to + swapspace by tmpfs. + + If you are unsure as to whether this is required, answer N. + +config TRUSTED_KEYS + tristate "TRUSTED KEYS" + depends on KEYS && TCG_TPM + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_SHA1 + help + This option provides support for creating, sealing, and unsealing + keys in the kernel. Trusted keys are random number symmetric keys, + generated and RSA-sealed by the TPM. The TPM only unseals the keys, + if the boot PCRs and other criteria match. Userspace will only ever + see encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +config ENCRYPTED_KEYS + tristate "ENCRYPTED KEYS" + depends on KEYS + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_SHA256 + select CRYPTO_RNG + help + This option provides support for create/encrypting/decrypting keys + in the kernel. Encrypted keys are kernel generated random numbers, + which are encrypted/decrypted with a 'master' symmetric key. The + 'master' key can be either a trusted-key or user-key type. + Userspace only ever sees/stores encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +config KEYS_DEBUG_PROC_KEYS + bool "Enable the /proc/keys file by which keys may be viewed" + depends on KEYS + help + This option turns on support for the /proc/keys file - through which + can be listed all the keys on the system that are viewable by the + reading process. + + The only keys included in the list are those that grant View + permission to the reading process whether or not it possesses them. + Note that LSM security checks are still performed, and may further + filter out keys that the current process is not authorised to view. + + Only key attributes are listed here; key payloads are not included in + the resulting table. + + If you are unsure as to whether this is required, answer N. diff --git a/security/keys/Makefile b/security/keys/Makefile index 1bf090a885f..dfb3a7beded 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -2,6 +2,9 @@ # Makefile for key management # +# +# Core +# obj-y := \ gc.o \ key.o \ @@ -12,9 +15,14 @@ obj-y := \ request_key.o \ request_key_auth.o \ user_defined.o - -obj-$(CONFIG_TRUSTED_KEYS) += trusted.o -obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_SYSCTL) += sysctl.o +obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o + +# +# Key types +# +obj-$(CONFIG_BIG_KEYS) += big_key.o +obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ diff --git a/security/keys/big_key.c b/security/keys/big_key.c new file mode 100644 index 00000000000..8137b27d641 --- /dev/null +++ b/security/keys/big_key.c @@ -0,0 +1,207 @@ +/* Large capacity key type + * + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/file.h> +#include <linux/shmem_fs.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <keys/big_key-type.h> + +MODULE_LICENSE("GPL"); + +/* + * If the data is under this limit, there's no point creating a shm file to + * hold it as the permanently resident metadata for the shmem fs will be at + * least as large as the data. + */ +#define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry)) + +/* + * big_key defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_big_key = { + .name = "big_key", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = big_key_instantiate, + .match = user_match, + .revoke = big_key_revoke, + .destroy = big_key_destroy, + .describe = big_key_describe, + .read = big_key_read, +}; + +/* + * Instantiate a big key + */ +int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +{ + struct path *path = (struct path *)&key->payload.data2; + struct file *file; + ssize_t written; + size_t datalen = prep->datalen; + int ret; + + ret = -EINVAL; + if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data) + goto error; + + /* Set an arbitrary quota */ + ret = key_payload_reserve(key, 16); + if (ret < 0) + goto error; + + key->type_data.x[1] = datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + /* Create a shmem file to store the data in. This will permit the data + * to be swapped out if needed. + * + * TODO: Encrypt the stored data with a temporary key. + */ + file = shmem_kernel_file_setup("", datalen, 0); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err_quota; + } + + written = kernel_write(file, prep->data, prep->datalen, 0); + if (written != datalen) { + ret = written; + if (written >= 0) + ret = -ENOMEM; + goto err_fput; + } + + /* Pin the mount and dentry to the key so that we can open it again + * later + */ + *path = file->f_path; + path_get(path); + fput(file); + } else { + /* Just store the data in a buffer */ + void *data = kmalloc(datalen, GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err_quota; + } + + key->payload.data = memcpy(data, prep->data, prep->datalen); + } + return 0; + +err_fput: + fput(file); +err_quota: + key_payload_reserve(key, 0); +error: + return ret; +} + +/* + * dispose of the links from a revoked keyring + * - called with the key sem write-locked + */ +void big_key_revoke(struct key *key) +{ + struct path *path = (struct path *)&key->payload.data2; + + /* clear the quota */ + key_payload_reserve(key, 0); + if (key_is_instantiated(key) && key->type_data.x[1] > BIG_KEY_FILE_THRESHOLD) + vfs_truncate(path, 0); +} + +/* + * dispose of the data dangling from the corpse of a big_key key + */ +void big_key_destroy(struct key *key) +{ + if (key->type_data.x[1] > BIG_KEY_FILE_THRESHOLD) { + struct path *path = (struct path *)&key->payload.data2; + path_put(path); + path->mnt = NULL; + path->dentry = NULL; + } else { + kfree(key->payload.data); + key->payload.data = NULL; + } +} + +/* + * describe the big_key key + */ +void big_key_describe(const struct key *key, struct seq_file *m) +{ + unsigned long datalen = key->type_data.x[1]; + + seq_puts(m, key->description); + + if (key_is_instantiated(key)) + seq_printf(m, ": %lu [%s]", + datalen, + datalen > BIG_KEY_FILE_THRESHOLD ? "file" : "buff"); +} + +/* + * read the key data + * - the key's semaphore is read-locked + */ +long big_key_read(const struct key *key, char __user *buffer, size_t buflen) +{ + unsigned long datalen = key->type_data.x[1]; + long ret; + + if (!buffer || buflen < datalen) + return datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + struct path *path = (struct path *)&key->payload.data2; + struct file *file; + loff_t pos; + + file = dentry_open(path, O_RDONLY, current_cred()); + if (IS_ERR(file)) + return PTR_ERR(file); + + pos = 0; + ret = vfs_read(file, buffer, datalen, &pos); + fput(file); + if (ret >= 0 && ret != datalen) + ret = -EIO; + } else { + ret = datalen; + if (copy_to_user(buffer, key->payload.data, datalen) != 0) + ret = -EFAULT; + } + + return ret; +} + +/* + * Module stuff + */ +static int __init big_key_init(void) +{ + return register_key_type(&key_type_big_key); +} + +static void __exit big_key_cleanup(void) +{ + unregister_key_type(&key_type_big_key); +} + +module_init(big_key_init); +module_exit(big_key_cleanup); diff --git a/security/keys/compat.c b/security/keys/compat.c index 07a5f35e397..347896548ad 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -12,9 +12,52 @@ #include <linux/syscalls.h> #include <linux/keyctl.h> #include <linux/compat.h> +#include <linux/slab.h> #include "internal.h" /* + * Instantiate a key with the specified compatibility multipart payload and + * link the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +static long compat_keyctl_instantiate_key_iov( + key_serial_t id, + const struct compat_iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + long ret; + + if (!_payload_iov || !ioc) + goto no_payload; + + ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), + iovstack, &iov); + if (ret < 0) + goto err; + if (ret == 0) + goto no_payload_free; + + ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); +err: + if (iov != iovstack) + kfree(iov); + return ret; + +no_payload_free: + if (iov != iovstack) + kfree(iov); +no_payload: + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* * The key control system call, 32-bit compatibility version for 64-bit archs * * This should only be called if the 64-bit arch uses weird pointers in 32-bit @@ -22,8 +65,8 @@ * taking a 32-bit syscall are zero. If you can, you should call sys_keyctl() * directly. */ -asmlinkage long compat_sys_keyctl(u32 option, - u32 arg2, u32 arg3, u32 arg4, u32 arg5) +COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, + u32, arg2, u32, arg3, u32, arg4, u32, arg5) { switch (option) { case KEYCTL_GET_KEYRING_ID: @@ -85,6 +128,19 @@ asmlinkage long compat_sys_keyctl(u32 option, case KEYCTL_SESSION_TO_PARENT: return keyctl_session_to_parent(); + case KEYCTL_REJECT: + return keyctl_reject_key(arg2, arg3, arg4, arg5); + + case KEYCTL_INSTANTIATE_IOV: + return compat_keyctl_instantiate_key_iov( + arg2, compat_ptr(arg3), arg4, arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key(arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent(arg2, arg3); + default: return -EOPNOTSUPP; } diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile new file mode 100644 index 00000000000..d6f8433250a --- /dev/null +++ b/security/keys/encrypted-keys/Makefile @@ -0,0 +1,10 @@ +# +# Makefile for encrypted keys +# + +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys.o + +encrypted-keys-y := encrypted.o ecryptfs_format.o +masterkey-$(CONFIG_TRUSTED_KEYS) := masterkey_trusted.o +masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS) := masterkey_trusted.o +encrypted-keys-y += $(masterkey-y) $(masterkey-m-m) diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c new file mode 100644 index 00000000000..6daa3b6ff9e --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.c @@ -0,0 +1,81 @@ +/* + * ecryptfs_format.c: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#include <linux/module.h> +#include "ecryptfs_format.h" + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) +{ + return auth_tok->token.password.session_key_encryption_key; +} +EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); + +/* + * ecryptfs_get_versions() + * + * Source code taken from the software 'ecryptfs-utils' version 83. + * + */ +void ecryptfs_get_versions(int *major, int *minor, int *file_version) +{ + *major = ECRYPTFS_VERSION_MAJOR; + *minor = ECRYPTFS_VERSION_MINOR; + if (file_version) + *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; +} +EXPORT_SYMBOL(ecryptfs_get_versions); + +/* + * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure + * + * Fill the ecryptfs_auth_tok structure with required ecryptfs data. + * The source code is inspired to the original function generate_payload() + * shipped with the software 'ecryptfs-utils' version 83. + * + */ +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc) +{ + int major, minor; + + ecryptfs_get_versions(&major, &minor, NULL); + auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) + | ((uint16_t)minor & 0x00FF)); + auth_tok->token_type = ECRYPTFS_PASSWORD; + strncpy((char *)auth_tok->token.password.signature, key_desc, + ECRYPTFS_PASSWORD_SIG_SIZE); + auth_tok->token.password.session_key_encryption_key_bytes = + ECRYPTFS_MAX_KEY_BYTES; + /* + * Removed auth_tok->token.password.salt and + * auth_tok->token.password.session_key_encryption_key + * initialization from the original code + */ + /* TODO: Make the hash parameterizable via policy */ + auth_tok->token.password.flags |= + ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; + /* The kernel code will encrypt the session key. */ + auth_tok->session_key.encrypted_key[0] = 0; + auth_tok->session_key.encrypted_key_size = 0; + /* Default; subject to change by kernel eCryptfs */ + auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; + auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); + return 0; +} +EXPORT_SYMBOL(ecryptfs_fill_auth_tok); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/ecryptfs_format.h b/security/keys/encrypted-keys/ecryptfs_format.h new file mode 100644 index 00000000000..40294de238b --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.h @@ -0,0 +1,30 @@ +/* + * ecryptfs_format.h: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#ifndef __KEYS_ECRYPTFS_H +#define __KEYS_ECRYPTFS_H + +#include <linux/ecryptfs.h> + +#define PGP_DIGEST_ALGO_SHA512 10 + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); +void ecryptfs_get_versions(int *major, int *minor, int *file_version); +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc); + +#endif /* __KEYS_ECRYPTFS_H */ diff --git a/security/keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 9e7e4ce3fae..5fe443d120a 100644 --- a/security/keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -1,14 +1,17 @@ /* * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it * - * Author: + * Authors: * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2 of the License. * - * See Documentation/keys-trusted-encrypted.txt + * See Documentation/security/keys-trusted-encrypted.txt */ #include <linux/uaccess.h> @@ -26,22 +29,27 @@ #include <linux/rcupdate.h> #include <linux/scatterlist.h> #include <linux/crypto.h> +#include <linux/ctype.h> #include <crypto/hash.h> #include <crypto/sha.h> #include <crypto/aes.h> #include "encrypted.h" +#include "ecryptfs_format.h" static const char KEY_TRUSTED_PREFIX[] = "trusted:"; static const char KEY_USER_PREFIX[] = "user:"; static const char hash_alg[] = "sha256"; static const char hmac_alg[] = "hmac(sha256)"; static const char blkcipher_alg[] = "cbc(aes)"; +static const char key_format_default[] = "default"; +static const char key_format_ecryptfs[] = "ecryptfs"; static unsigned int ivsize; static int blksize; #define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) #define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) +#define KEY_ECRYPTFS_DESC_LEN 16 #define HASH_SIZE SHA256_DIGEST_SIZE #define MAX_DATA_SIZE 4096 #define MIN_DATA_SIZE 20 @@ -58,6 +66,16 @@ enum { Opt_err = -1, Opt_new, Opt_load, Opt_update }; +enum { + Opt_error = -1, Opt_default, Opt_ecryptfs +}; + +static const match_table_t key_format_tokens = { + {Opt_default, "default"}, + {Opt_ecryptfs, "ecryptfs"}, + {Opt_error, NULL} +}; + static const match_table_t key_tokens = { {Opt_new, "new"}, {Opt_load, "load"}, @@ -82,9 +100,37 @@ static int aes_get_sizes(void) } /* + * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key + * + * The description of a encrypted key with format 'ecryptfs' must contain + * exactly 16 hexadecimal characters. + * + */ +static int valid_ecryptfs_desc(const char *ecryptfs_desc) +{ + int i; + + if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { + pr_err("encrypted_key: key description must be %d hexadecimal " + "characters long\n", KEY_ECRYPTFS_DESC_LEN); + return -EINVAL; + } + + for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { + if (!isxdigit(ecryptfs_desc[i])) { + pr_err("encrypted_key: key description must contain " + "only hexadecimal characters\n"); + return -EINVAL; + } + } + + return 0; +} + +/* * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key * - * key-type:= "trusted:" | "encrypted:" + * key-type:= "trusted:" | "user:" * desc:= master-key description * * Verify that 'key-type' is valid and that 'desc' exists. On key update, @@ -118,8 +164,9 @@ out: * datablob_parse - parse the keyctl data * * datablob format: - * new <master-key name> <decrypted data length> - * load <master-key name> <decrypted data length> <encrypted iv + data> + * new [<format>] <master-key name> <decrypted data length> + * load [<format>] <master-key name> <decrypted data length> + * <encrypted iv + data> * update <new-master-key name> * * Tokenizes a copy of the keyctl data, returning a pointer to each token, @@ -127,52 +174,95 @@ out: * * On success returns 0, otherwise -EINVAL. */ -static int datablob_parse(char *datablob, char **master_desc, - char **decrypted_datalen, char **hex_encoded_iv) +static int datablob_parse(char *datablob, const char **format, + char **master_desc, char **decrypted_datalen, + char **hex_encoded_iv) { substring_t args[MAX_OPT_ARGS]; int ret = -EINVAL; int key_cmd; - char *p; + int key_format; + char *p, *keyword; + keyword = strsep(&datablob, " \t"); + if (!keyword) { + pr_info("encrypted_key: insufficient parameters specified\n"); + return ret; + } + key_cmd = match_token(keyword, key_tokens, args); + + /* Get optional format: default | ecryptfs */ p = strsep(&datablob, " \t"); - if (!p) + if (!p) { + pr_err("encrypted_key: insufficient parameters specified\n"); return ret; - key_cmd = match_token(p, key_tokens, args); + } - *master_desc = strsep(&datablob, " \t"); - if (!*master_desc) + key_format = match_token(p, key_format_tokens, args); + switch (key_format) { + case Opt_ecryptfs: + case Opt_default: + *format = p; + *master_desc = strsep(&datablob, " \t"); + break; + case Opt_error: + *master_desc = p; + break; + } + + if (!*master_desc) { + pr_info("encrypted_key: master key parameter is missing\n"); goto out; + } - if (valid_master_desc(*master_desc, NULL) < 0) + if (valid_master_desc(*master_desc, NULL) < 0) { + pr_info("encrypted_key: master key parameter \'%s\' " + "is invalid\n", *master_desc); goto out; + } if (decrypted_datalen) { *decrypted_datalen = strsep(&datablob, " \t"); - if (!*decrypted_datalen) + if (!*decrypted_datalen) { + pr_info("encrypted_key: keylen parameter is missing\n"); goto out; + } } switch (key_cmd) { case Opt_new: - if (!decrypted_datalen) + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); break; + } ret = 0; break; case Opt_load: - if (!decrypted_datalen) + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); break; + } *hex_encoded_iv = strsep(&datablob, " \t"); - if (!*hex_encoded_iv) + if (!*hex_encoded_iv) { + pr_info("encrypted_key: hex blob is missing\n"); break; + } ret = 0; break; case Opt_update: - if (decrypted_datalen) + if (decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .instantiate method\n", + keyword); break; + } ret = 0; break; case Opt_err: + pr_info("encrypted_key: keyword \'%s\' not recognized\n", + keyword); break; } out: @@ -197,43 +287,18 @@ static char *datablob_format(struct encrypted_key_payload *epayload, ascii_buf[asciiblob_len] = '\0'; /* copy datablob master_desc and datalen strings */ - len = sprintf(ascii_buf, "%s %s ", epayload->master_desc, - epayload->datalen); + len = sprintf(ascii_buf, "%s %s %s ", epayload->format, + epayload->master_desc, epayload->datalen); /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ bufp = &ascii_buf[len]; for (i = 0; i < (asciiblob_len - len) / 2; i++) - bufp = pack_hex_byte(bufp, iv[i]); + bufp = hex_byte_pack(bufp, iv[i]); out: return ascii_buf; } /* - * request_trusted_key - request the trusted key - * - * Trusted keys are sealed to PCRs and other metadata. Although userspace - * manages both trusted/encrypted key-types, like the encrypted key type - * data, trusted key type data is not visible decrypted from userspace. - */ -static struct key *request_trusted_key(const char *trusted_desc, - u8 **master_key, size_t *master_keylen) -{ - struct trusted_key_payload *tpayload; - struct key *tkey; - - tkey = request_key(&key_type_trusted, trusted_desc, NULL); - if (IS_ERR(tkey)) - goto error; - - down_read(&tkey->sem); - tpayload = rcu_dereference(tkey->payload.data); - *master_key = tpayload->key; - *master_keylen = tpayload->key_len; -error: - return tkey; -} - -/* * request_user_key - request the user key * * Use a user provided key to encrypt/decrypt an encrypted-key. @@ -249,7 +314,7 @@ static struct key *request_user_key(const char *master_desc, u8 **master_key, goto error; down_read(&ukey->sem); - upayload = rcu_dereference(ukey->payload.data); + upayload = ukey->payload.data; *master_key = upayload->data; *master_keylen = upayload->datalen; error: @@ -378,11 +443,19 @@ static struct key *request_master_key(struct encrypted_key_payload *epayload, } else goto out; - if (IS_ERR(mkey)) - pr_info("encrypted_key: key %s not found", - epayload->master_desc); - if (mkey) - dump_master_key(*master_key, *master_keylen); + if (IS_ERR(mkey)) { + int ret = PTR_ERR(mkey); + + if (ret == -ENOTSUPP) + pr_info("encrypted_key: key %s not supported", + epayload->master_desc); + else + pr_info("encrypted_key: key %s not found", + epayload->master_desc); + goto out; + } + + dump_master_key(*master_key, *master_keylen); out: return mkey; } @@ -439,9 +512,9 @@ static int datablob_hmac_append(struct encrypted_key_payload *epayload, if (ret < 0) goto out; - digest = epayload->master_desc + epayload->datablob_len; + digest = epayload->format + epayload->datablob_len; ret = calc_hmac(digest, derived_key, sizeof derived_key, - epayload->master_desc, epayload->datablob_len); + epayload->format, epayload->datablob_len); if (!ret) dump_hmac(NULL, digest, HASH_SIZE); out: @@ -450,26 +523,35 @@ out: /* verify HMAC before decrypting encrypted key */ static int datablob_hmac_verify(struct encrypted_key_payload *epayload, - const u8 *master_key, size_t master_keylen) + const u8 *format, const u8 *master_key, + size_t master_keylen) { u8 derived_key[HASH_SIZE]; u8 digest[HASH_SIZE]; int ret; + char *p; + unsigned short len; ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); if (ret < 0) goto out; - ret = calc_hmac(digest, derived_key, sizeof derived_key, - epayload->master_desc, epayload->datablob_len); + len = epayload->datablob_len; + if (!format) { + p = epayload->master_desc; + len -= strlen(epayload->format) + 1; + } else + p = epayload->format; + + ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); if (ret < 0) goto out; - ret = memcmp(digest, epayload->master_desc + epayload->datablob_len, + ret = memcmp(digest, epayload->format + epayload->datablob_len, sizeof digest); if (ret) { ret = -EINVAL; dump_hmac("datablob", - epayload->master_desc + epayload->datablob_len, + epayload->format + epayload->datablob_len, HASH_SIZE); dump_hmac("calc", digest, HASH_SIZE); } @@ -514,43 +596,60 @@ out: /* Allocate memory for decrypted key and datablob. */ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, + const char *format, const char *master_desc, const char *datalen) { struct encrypted_key_payload *epayload = NULL; unsigned short datablob_len; unsigned short decrypted_datalen; + unsigned short payload_datalen; unsigned int encrypted_datalen; + unsigned int format_len; long dlen; int ret; - ret = strict_strtol(datalen, 10, &dlen); + ret = kstrtol(datalen, 10, &dlen); if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) return ERR_PTR(-EINVAL); + format_len = (!format) ? strlen(key_format_default) : strlen(format); decrypted_datalen = dlen; + payload_datalen = decrypted_datalen; + if (format && !strcmp(format, key_format_ecryptfs)) { + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { + pr_err("encrypted_key: keylen for the ecryptfs format " + "must be equal to %d bytes\n", + ECRYPTFS_MAX_KEY_BYTES); + return ERR_PTR(-EINVAL); + } + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; + payload_datalen = sizeof(struct ecryptfs_auth_tok); + } + encrypted_datalen = roundup(decrypted_datalen, blksize); - datablob_len = strlen(master_desc) + 1 + strlen(datalen) + 1 - + ivsize + 1 + encrypted_datalen; + datablob_len = format_len + 1 + strlen(master_desc) + 1 + + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; - ret = key_payload_reserve(key, decrypted_datalen + datablob_len + ret = key_payload_reserve(key, payload_datalen + datablob_len + HASH_SIZE + 1); if (ret < 0) return ERR_PTR(ret); - epayload = kzalloc(sizeof(*epayload) + decrypted_datalen + + epayload = kzalloc(sizeof(*epayload) + payload_datalen + datablob_len + HASH_SIZE + 1, GFP_KERNEL); if (!epayload) return ERR_PTR(-ENOMEM); + epayload->payload_datalen = payload_datalen; epayload->decrypted_datalen = decrypted_datalen; epayload->datablob_len = datablob_len; return epayload; } static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, - const char *hex_encoded_iv) + const char *format, const char *hex_encoded_iv) { struct key *mkey; u8 derived_key[HASH_SIZE]; @@ -568,17 +667,25 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, return -EINVAL; hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; - hex2bin(epayload->iv, hex_encoded_iv, ivsize); - hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen); + ret = hex2bin(epayload->iv, hex_encoded_iv, ivsize); + if (ret < 0) + return -EINVAL; + ret = hex2bin(epayload->encrypted_data, hex_encoded_data, + encrypted_datalen); + if (ret < 0) + return -EINVAL; - hmac = epayload->master_desc + epayload->datablob_len; - hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE); + hmac = epayload->format + epayload->datablob_len; + ret = hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), + HASH_SIZE); + if (ret < 0) + return -EINVAL; mkey = request_master_key(epayload, &master_key, &master_keylen); if (IS_ERR(mkey)) return PTR_ERR(mkey); - ret = datablob_hmac_verify(epayload, master_key, master_keylen); + ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); if (ret < 0) { pr_err("encrypted_key: bad hmac (%d)\n", ret); goto out; @@ -598,13 +705,28 @@ out: } static void __ekey_init(struct encrypted_key_payload *epayload, - const char *master_desc, const char *datalen) + const char *format, const char *master_desc, + const char *datalen) { - epayload->master_desc = epayload->decrypted_data - + epayload->decrypted_datalen; + unsigned int format_len; + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + epayload->format = epayload->payload_data + epayload->payload_datalen; + epayload->master_desc = epayload->format + format_len + 1; epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; epayload->iv = epayload->datalen + strlen(datalen) + 1; epayload->encrypted_data = epayload->iv + ivsize + 1; + epayload->decrypted_data = epayload->payload_data; + + if (!format) + memcpy(epayload->format, key_format_default, format_len); + else { + if (!strcmp(format, key_format_ecryptfs)) + epayload->decrypted_data = + ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); + + memcpy(epayload->format, format, format_len); + } memcpy(epayload->master_desc, master_desc, strlen(master_desc)); memcpy(epayload->datalen, datalen, strlen(datalen)); @@ -617,19 +739,29 @@ static void __ekey_init(struct encrypted_key_payload *epayload, * itself. For an old key, decrypt the hex encoded data. */ static int encrypted_init(struct encrypted_key_payload *epayload, + const char *key_desc, const char *format, const char *master_desc, const char *datalen, const char *hex_encoded_iv) { int ret = 0; - __ekey_init(epayload, master_desc, datalen); + if (format && !strcmp(format, key_format_ecryptfs)) { + ret = valid_ecryptfs_desc(key_desc); + if (ret < 0) + return ret; + + ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, + key_desc); + } + + __ekey_init(epayload, format, master_desc, datalen); if (!hex_encoded_iv) { get_random_bytes(epayload->iv, ivsize); get_random_bytes(epayload->decrypted_data, epayload->decrypted_datalen); } else - ret = encrypted_key_decrypt(epayload, hex_encoded_iv); + ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); return ret; } @@ -641,42 +773,45 @@ static int encrypted_init(struct encrypted_key_payload *epayload, * * On success, return 0. Otherwise return errno. */ -static int encrypted_instantiate(struct key *key, const void *data, - size_t datalen) +static int encrypted_instantiate(struct key *key, + struct key_preparsed_payload *prep) { struct encrypted_key_payload *epayload = NULL; char *datablob = NULL; + const char *format = NULL; char *master_desc = NULL; char *decrypted_datalen = NULL; char *hex_encoded_iv = NULL; + size_t datalen = prep->datalen; int ret; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; datablob = kmalloc(datalen + 1, GFP_KERNEL); if (!datablob) return -ENOMEM; datablob[datalen] = 0; - memcpy(datablob, data, datalen); - ret = datablob_parse(datablob, &master_desc, &decrypted_datalen, - &hex_encoded_iv); + memcpy(datablob, prep->data, datalen); + ret = datablob_parse(datablob, &format, &master_desc, + &decrypted_datalen, &hex_encoded_iv); if (ret < 0) goto out; - epayload = encrypted_key_alloc(key, master_desc, decrypted_datalen); + epayload = encrypted_key_alloc(key, format, master_desc, + decrypted_datalen); if (IS_ERR(epayload)) { ret = PTR_ERR(epayload); goto out; } - ret = encrypted_init(epayload, master_desc, decrypted_datalen, - hex_encoded_iv); + ret = encrypted_init(epayload, key->description, format, master_desc, + decrypted_datalen, hex_encoded_iv); if (ret < 0) { kfree(epayload); goto out; } - rcu_assign_pointer(key->payload.data, epayload); + rcu_assign_keypointer(key, epayload); out: kfree(datablob); return ret; @@ -700,15 +835,17 @@ static void encrypted_rcu_free(struct rcu_head *rcu) * * On success, return 0. Otherwise return errno. */ -static int encrypted_update(struct key *key, const void *data, size_t datalen) +static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) { struct encrypted_key_payload *epayload = key->payload.data; struct encrypted_key_payload *new_epayload; char *buf; char *new_master_desc = NULL; + const char *format = NULL; + size_t datalen = prep->datalen; int ret = 0; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; buf = kmalloc(datalen + 1, GFP_KERNEL); @@ -716,8 +853,8 @@ static int encrypted_update(struct key *key, const void *data, size_t datalen) return -ENOMEM; buf[datalen] = 0; - memcpy(buf, data, datalen); - ret = datablob_parse(buf, &new_master_desc, NULL, NULL); + memcpy(buf, prep->data, datalen); + ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL); if (ret < 0) goto out; @@ -725,20 +862,21 @@ static int encrypted_update(struct key *key, const void *data, size_t datalen) if (ret < 0) goto out; - new_epayload = encrypted_key_alloc(key, new_master_desc, - epayload->datalen); + new_epayload = encrypted_key_alloc(key, epayload->format, + new_master_desc, epayload->datalen); if (IS_ERR(new_epayload)) { ret = PTR_ERR(new_epayload); goto out; } - __ekey_init(new_epayload, new_master_desc, epayload->datalen); + __ekey_init(new_epayload, epayload->format, new_master_desc, + epayload->datalen); memcpy(new_epayload->iv, epayload->iv, ivsize); - memcpy(new_epayload->decrypted_data, epayload->decrypted_data, - epayload->decrypted_datalen); + memcpy(new_epayload->payload_data, epayload->payload_data, + epayload->payload_datalen); - rcu_assign_pointer(key->payload.data, new_epayload); + rcu_assign_keypointer(key, new_epayload); call_rcu(&epayload->rcu, encrypted_rcu_free); out: kfree(buf); @@ -765,8 +903,7 @@ static long encrypted_read(const struct key *key, char __user *buffer, size_t asciiblob_len; int ret; - epayload = rcu_dereference_protected(key->payload.data, - rwsem_is_locked(&((struct key *)key)->sem)); + epayload = rcu_dereference_key(key); /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ asciiblob_len = epayload->datablob_len + ivsize + 1 diff --git a/security/keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h index cef5e2f2b7d..8136a2d44c6 100644 --- a/security/keys/encrypted.h +++ b/security/keys/encrypted-keys/encrypted.h @@ -2,6 +2,18 @@ #define __ENCRYPTED_KEY_H #define ENCRYPTED_DEBUG 0 +#if defined(CONFIG_TRUSTED_KEYS) || \ + (defined(CONFIG_TRUSTED_KEYS_MODULE) && defined(CONFIG_ENCRYPTED_KEYS_MODULE)) +extern struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen); +#else +static inline struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, + size_t *master_keylen) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif #if ENCRYPTED_DEBUG static inline void dump_master_key(const u8 *master_key, size_t master_keylen) diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c new file mode 100644 index 00000000000..013f7e5d3a2 --- /dev/null +++ b/security/keys/encrypted-keys/masterkey_trusted.c @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/err.h> +#include <keys/trusted-type.h> +#include <keys/encrypted-type.h> +#include "encrypted.h" + +/* + * request_trusted_key - request the trusted key + * + * Trusted keys are sealed to PCRs and other metadata. Although userspace + * manages both trusted/encrypted key-types, like the encrypted key type + * data, trusted key type data is not visible decrypted from userspace. + */ +struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen) +{ + struct trusted_key_payload *tpayload; + struct key *tkey; + + tkey = request_key(&key_type_trusted, trusted_desc, NULL); + if (IS_ERR(tkey)) + goto error; + + down_read(&tkey->sem); + tpayload = tkey->payload.data; + *master_key = tpayload->key; + *master_keylen = tpayload->key_len; +error: + return tkey; +} diff --git a/security/keys/gc.c b/security/keys/gc.c index 89df6b5f203..d3222b6d7d5 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -1,6 +1,6 @@ /* Key garbage collector * - * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -10,6 +10,8 @@ */ #include <linux/module.h> +#include <linux/slab.h> +#include <linux/security.h> #include <keys/keyring-type.h> #include "internal.h" @@ -19,17 +21,33 @@ unsigned key_gc_delay = 5 * 60; /* - * Reaper + * Reaper for unused keys. + */ +static void key_garbage_collector(struct work_struct *work); +DECLARE_WORK(key_gc_work, key_garbage_collector); + +/* + * Reaper for links from keyrings to dead keys. */ static void key_gc_timer_func(unsigned long); -static void key_garbage_collector(struct work_struct *); static DEFINE_TIMER(key_gc_timer, key_gc_timer_func, 0, 0); -static DECLARE_WORK(key_gc_work, key_garbage_collector); -static key_serial_t key_gc_cursor; /* the last key the gc considered */ -static bool key_gc_again; -static unsigned long key_gc_executing; + static time_t key_gc_next_run = LONG_MAX; -static time_t key_gc_new_timer; +static struct key_type *key_gc_dead_keytype; + +static unsigned long key_gc_flags; +#define KEY_GC_KEY_EXPIRED 0 /* A key expired and needs unlinking */ +#define KEY_GC_REAP_KEYTYPE 1 /* A keytype is being unregistered */ +#define KEY_GC_REAPING_KEYTYPE 2 /* Cleared when keytype reaped */ + + +/* + * Any key whose type gets unregistered will be re-typed to this if it can't be + * immediately unlinked. + */ +struct key_type key_type_dead = { + .name = "dead", +}; /* * Schedule a garbage collection run. @@ -42,181 +60,308 @@ void key_schedule_gc(time_t gc_at) kenter("%ld", gc_at - now); - if (gc_at <= now) { + if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) { + kdebug("IMMEDIATE"); schedule_work(&key_gc_work); } else if (gc_at < key_gc_next_run) { + kdebug("DEFERRED"); + key_gc_next_run = gc_at; expires = jiffies + (gc_at - now) * HZ; mod_timer(&key_gc_timer, expires); } } /* - * The garbage collector timer kicked off + * Schedule a dead links collection run. + */ +void key_schedule_gc_links(void) +{ + set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags); + schedule_work(&key_gc_work); +} + +/* + * Some key's cleanup time was met after it expired, so we need to get the + * reaper to go through a cycle finding expired keys. */ static void key_gc_timer_func(unsigned long data) { kenter(""); key_gc_next_run = LONG_MAX; - schedule_work(&key_gc_work); + key_schedule_gc_links(); +} + +/* + * wait_on_bit() sleep function for uninterruptible waiting + */ +static int key_gc_wait_bit(void *flags) +{ + schedule(); + return 0; } /* - * Garbage collect pointers from a keyring. + * Reap keys of dead type. * - * Return true if we altered the keyring. + * We use three flags to make sure we see three complete cycles of the garbage + * collector: the first to mark keys of that type as being dead, the second to + * collect dead links and the third to clean up the dead keys. We have to be + * careful as there may already be a cycle in progress. + * + * The caller must be holding key_types_sem. */ -static bool key_gc_keyring(struct key *keyring, time_t limit) - __releases(key_serial_lock) +void key_gc_keytype(struct key_type *ktype) { - struct keyring_list *klist; - struct key *key; - int loop; + kenter("%s", ktype->name); - kenter("%x", key_serial(keyring)); + key_gc_dead_keytype = ktype; + set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + smp_mb(); + set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags); - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) - goto dont_gc; + kdebug("schedule"); + schedule_work(&key_gc_work); - /* scan the keyring looking for dead keys */ - rcu_read_lock(); - klist = rcu_dereference(keyring->payload.subscriptions); - if (!klist) - goto unlock_dont_gc; + kdebug("sleep"); + wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit, + TASK_UNINTERRUPTIBLE); - for (loop = klist->nkeys - 1; loop >= 0; loop--) { - key = klist->keys[loop]; - if (test_bit(KEY_FLAG_DEAD, &key->flags) || - (key->expiry > 0 && key->expiry <= limit)) - goto do_gc; - } + key_gc_dead_keytype = NULL; + kleave(""); +} -unlock_dont_gc: - rcu_read_unlock(); -dont_gc: - kleave(" = false"); - return false; +/* + * Garbage collect a list of unreferenced, detached keys + */ +static noinline void key_gc_unused_keys(struct list_head *keys) +{ + while (!list_empty(keys)) { + struct key *key = + list_entry(keys->next, struct key, graveyard_link); + list_del(&key->graveyard_link); -do_gc: - rcu_read_unlock(); - key_gc_cursor = keyring->serial; - key_get(keyring); - spin_unlock(&key_serial_lock); - keyring_gc(keyring, limit); - key_put(keyring); - kleave(" = true"); - return true; + kdebug("- %u", key->serial); + key_check(key); + + security_key_free(key); + + /* deal with the user's key tracking and quota */ + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + spin_lock(&key->user->lock); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock(&key->user->lock); + } + + atomic_dec(&key->user->nkeys); + if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + atomic_dec(&key->user->nikeys); + + key_user_put(key->user); + + /* now throw away the key memory */ + if (key->type->destroy) + key->type->destroy(key); + + kfree(key->description); + +#ifdef KEY_DEBUGGING + key->magic = KEY_DEBUG_MAGIC_X; +#endif + kmem_cache_free(key_jar, key); + } } /* - * Garbage collector for keys. This involves scanning the keyrings for dead, - * expired and revoked keys that have overstayed their welcome + * Garbage collector for unused keys. + * + * This is done in process context so that we don't have to disable interrupts + * all over the place. key_put() schedules this rather than trying to do the + * cleanup itself, which means key_put() doesn't have to sleep. */ static void key_garbage_collector(struct work_struct *work) { - struct rb_node *rb; - key_serial_t cursor; - struct key *key, *xkey; - time_t new_timer = LONG_MAX, limit, now; - - now = current_kernel_time().tv_sec; - kenter("[%x,%ld]", key_gc_cursor, key_gc_new_timer - now); - - if (test_and_set_bit(0, &key_gc_executing)) { - key_schedule_gc(current_kernel_time().tv_sec + 1); - kleave(" [busy; deferring]"); - return; - } + static LIST_HEAD(graveyard); + static u8 gc_state; /* Internal persistent state */ +#define KEY_GC_REAP_AGAIN 0x01 /* - Need another cycle */ +#define KEY_GC_REAPING_LINKS 0x02 /* - We need to reap links */ +#define KEY_GC_SET_TIMER 0x04 /* - We need to restart the timer */ +#define KEY_GC_REAPING_DEAD_1 0x10 /* - We need to mark dead keys */ +#define KEY_GC_REAPING_DEAD_2 0x20 /* - We need to reap dead key links */ +#define KEY_GC_REAPING_DEAD_3 0x40 /* - We need to reap dead keys */ +#define KEY_GC_FOUND_DEAD_KEY 0x80 /* - We found at least one dead key */ - limit = now; + struct rb_node *cursor; + struct key *key; + time_t new_timer, limit; + + kenter("[%lx,%x]", key_gc_flags, gc_state); + + limit = current_kernel_time().tv_sec; if (limit > key_gc_delay) limit -= key_gc_delay; else limit = key_gc_delay; + /* Work out what we're going to be doing in this pass */ + gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2; + gc_state <<= 1; + if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_LINKS | KEY_GC_SET_TIMER; + + if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_DEAD_1; + kdebug("new pass %x", gc_state); + + new_timer = LONG_MAX; + + /* As only this function is permitted to remove things from the key + * serial tree, if cursor is non-NULL then it will always point to a + * valid node in the tree - even if lock got dropped. + */ spin_lock(&key_serial_lock); + cursor = rb_first(&key_serial_tree); - if (unlikely(RB_EMPTY_ROOT(&key_serial_tree))) { - spin_unlock(&key_serial_lock); - clear_bit(0, &key_gc_executing); - return; - } +continue_scanning: + while (cursor) { + key = rb_entry(cursor, struct key, serial_node); + cursor = rb_next(cursor); - cursor = key_gc_cursor; - if (cursor < 0) - cursor = 0; - if (cursor > 0) - new_timer = key_gc_new_timer; - else - key_gc_again = false; - - /* find the first key above the cursor */ - key = NULL; - rb = key_serial_tree.rb_node; - while (rb) { - xkey = rb_entry(rb, struct key, serial_node); - if (cursor < xkey->serial) { - key = xkey; - rb = rb->rb_left; - } else if (cursor > xkey->serial) { - rb = rb->rb_right; - } else { - rb = rb_next(rb); - if (!rb) - goto reached_the_end; - key = rb_entry(rb, struct key, serial_node); - break; + if (atomic_read(&key->usage) == 0) + goto found_unreferenced_key; + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) { + if (key->type == key_gc_dead_keytype) { + gc_state |= KEY_GC_FOUND_DEAD_KEY; + set_bit(KEY_FLAG_DEAD, &key->flags); + key->perm = 0; + goto skip_dead_key; + } } - } - if (!key) - goto reached_the_end; + if (gc_state & KEY_GC_SET_TIMER) { + if (key->expiry > limit && key->expiry < new_timer) { + kdebug("will expire %x in %ld", + key_serial(key), key->expiry - limit); + new_timer = key->expiry; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) + if (key->type == key_gc_dead_keytype) + gc_state |= KEY_GC_FOUND_DEAD_KEY; - /* trawl through the keys looking for keyrings */ - for (;;) { - if (key->expiry > limit && key->expiry < new_timer) { - kdebug("will expire %x in %ld", - key_serial(key), key->expiry - limit); - new_timer = key->expiry; + if ((gc_state & KEY_GC_REAPING_LINKS) || + unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) { + if (key->type == &key_type_keyring) + goto found_keyring; } - if (key->type == &key_type_keyring && - key_gc_keyring(key, limit)) - /* the gc had to release our lock so that the keyring - * could be modified, so we have to get it again */ - goto gc_released_our_lock; + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) + if (key->type == key_gc_dead_keytype) + goto destroy_dead_key; - rb = rb_next(&key->serial_node); - if (!rb) - goto reached_the_end; - key = rb_entry(rb, struct key, serial_node); + skip_dead_key: + if (spin_is_contended(&key_serial_lock) || need_resched()) + goto contended; } -gc_released_our_lock: - kdebug("gc_released_our_lock"); - key_gc_new_timer = new_timer; - key_gc_again = true; - clear_bit(0, &key_gc_executing); - schedule_work(&key_gc_work); - kleave(" [continue]"); - return; - - /* when we reach the end of the run, we set the timer for the next one */ -reached_the_end: - kdebug("reached_the_end"); +contended: spin_unlock(&key_serial_lock); - key_gc_new_timer = new_timer; - key_gc_cursor = 0; - clear_bit(0, &key_gc_executing); - - if (key_gc_again) { - /* there may have been a key that expired whilst we were - * scanning, so if we discarded any links we should do another - * scan */ - new_timer = now + 1; - key_schedule_gc(new_timer); - } else if (new_timer < LONG_MAX) { + +maybe_resched: + if (cursor) { + cond_resched(); + spin_lock(&key_serial_lock); + goto continue_scanning; + } + + /* We've completed the pass. Set the timer if we need to and queue a + * new cycle if necessary. We keep executing cycles until we find one + * where we didn't reap any keys. + */ + kdebug("pass complete"); + + if (gc_state & KEY_GC_SET_TIMER && new_timer != (time_t)LONG_MAX) { new_timer += key_gc_delay; key_schedule_gc(new_timer); } - kleave(" [end]"); + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) || + !list_empty(&graveyard)) { + /* Make sure that all pending keyring payload destructions are + * fulfilled and that people aren't now looking at dead or + * dying keys that they don't have a reference upon or a link + * to. + */ + kdebug("gc sync"); + synchronize_rcu(); + } + + if (!list_empty(&graveyard)) { + kdebug("gc keys"); + key_gc_unused_keys(&graveyard); + } + + if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 | + KEY_GC_REAPING_DEAD_2))) { + if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) { + /* No remaining dead keys: short circuit the remaining + * keytype reap cycles. + */ + kdebug("dead short"); + gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2); + gc_state |= KEY_GC_REAPING_DEAD_3; + } else { + gc_state |= KEY_GC_REAP_AGAIN; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) { + kdebug("dead wake"); + smp_mb(); + clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE); + } + + if (gc_state & KEY_GC_REAP_AGAIN) + schedule_work(&key_gc_work); + kleave(" [end %x]", gc_state); + return; + + /* We found an unreferenced key - once we've removed it from the tree, + * we can safely drop the lock. + */ +found_unreferenced_key: + kdebug("unrefd key %d", key->serial); + rb_erase(&key->serial_node, &key_serial_tree); + spin_unlock(&key_serial_lock); + + list_add_tail(&key->graveyard_link, &graveyard); + gc_state |= KEY_GC_REAP_AGAIN; + goto maybe_resched; + + /* We found a keyring and we need to check the payload for links to + * dead or expired keys. We don't flag another reap immediately as we + * have to wait for the old payload to be destroyed by RCU before we + * can reap the keys to which it refers. + */ +found_keyring: + spin_unlock(&key_serial_lock); + keyring_gc(key, limit); + goto maybe_resched; + + /* We found a dead key that is still referenced. Reset its type and + * destroy its payload with its semaphore held. + */ +destroy_dead_key: + spin_unlock(&key_serial_lock); + kdebug("destroy key %d", key->serial); + down_write(&key->sem); + key->type = &key_type_dead; + if (key_gc_dead_keytype->destroy) + key_gc_dead_keytype->destroy(key); + memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); + up_write(&key->sem); + goto maybe_resched; } diff --git a/security/keys/internal.h b/security/keys/internal.h index a52aa7c88b4..5f20da01fd8 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -14,6 +14,9 @@ #include <linux/sched.h> #include <linux/key-type.h> +#include <linux/task_work.h> + +struct iovec; #ifdef __KDEBUG #define kenter(FMT, ...) \ @@ -31,7 +34,9 @@ no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) #endif +extern struct key_type key_type_dead; extern struct key_type key_type_user; +extern struct key_type key_type_logon; /*****************************************************************************/ /* @@ -49,8 +54,7 @@ struct key_user { atomic_t usage; /* for accessing qnkeys & qnbytes */ atomic_t nkeys; /* number of keys */ atomic_t nikeys; /* number of instantiated keys */ - uid_t uid; - struct user_namespace *user_ns; + kuid_t uid; int qnkeys; /* number of keys allocated to this user */ int qnbytes; /* number of bytes allocated to this user */ }; @@ -59,8 +63,7 @@ extern struct rb_root key_user_tree; extern spinlock_t key_user_lock; extern struct key_user root_key_user; -extern struct key_user *key_user_lookup(uid_t uid, - struct user_namespace *user_ns); +extern struct key_user *key_user_lookup(kuid_t uid); extern void key_user_put(struct key_user *user); /* @@ -75,6 +78,7 @@ extern unsigned key_quota_maxbytes; #define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ +extern struct kmem_cache *key_jar; extern struct rb_root key_serial_tree; extern spinlock_t key_serial_lock; extern struct mutex key_construction_mutex; @@ -85,40 +89,53 @@ extern struct key_type *key_type_lookup(const char *type); extern void key_type_put(struct key_type *ktype); extern int __key_link_begin(struct key *keyring, - const struct key_type *type, - const char *description, - unsigned long *_prealloc); + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit); extern int __key_link_check_live_key(struct key *keyring, struct key *key); -extern void __key_link(struct key *keyring, struct key *key, - unsigned long *_prealloc); +extern void __key_link(struct key *key, struct assoc_array_edit **_edit); extern void __key_link_end(struct key *keyring, - struct key_type *type, - unsigned long prealloc); + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit); -extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, - const struct key_type *type, - const char *description, - key_perm_t perm); +extern key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key); extern struct key *keyring_search_instkey(struct key *keyring, key_serial_t target_id); +extern int iterate_over_keyring(const struct key *keyring, + int (*func)(const struct key *key, void *data), + void *data); + typedef int (*key_match_func_t)(const struct key *, const void *); +struct keyring_search_context { + struct keyring_index_key index_key; + const struct cred *cred; + key_match_func_t match; + const void *match_data; + unsigned flags; +#define KEYRING_SEARCH_LOOKUP_TYPE 0x0001 /* [as type->def_lookup_type] */ +#define KEYRING_SEARCH_NO_STATE_CHECK 0x0002 /* Skip state checks */ +#define KEYRING_SEARCH_DO_STATE_CHECK 0x0004 /* Override NO_STATE_CHECK */ +#define KEYRING_SEARCH_NO_UPDATE_TIME 0x0008 /* Don't update times */ +#define KEYRING_SEARCH_NO_CHECK_PERM 0x0010 /* Don't check permissions */ +#define KEYRING_SEARCH_DETECT_TOO_DEEP 0x0020 /* Give an error on excessive depth */ + + int (*iterator)(const void *object, void *iterator_data); + + /* Internal stuff */ + int skipped_ret; + bool possessed; + key_ref_t result; + struct timespec now; +}; + extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, - const struct cred *cred, - struct key_type *type, - const void *description, - key_match_func_t match); - -extern key_ref_t search_my_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - const struct cred *cred); -extern key_ref_t search_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - const struct cred *cred); + struct keyring_search_context *ctx); + +extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx); +extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx); extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); @@ -143,10 +160,14 @@ extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags, #define KEY_LOOKUP_FOR_UNLINK 0x04 extern long join_session_keyring(const char *name); +extern void key_change_session_keyring(struct callback_head *twork); +extern struct work_struct key_gc_work; extern unsigned key_gc_delay; extern void keyring_gc(struct key *keyring, time_t limit); -extern void key_schedule_gc(time_t expiry_at); +extern void key_schedule_gc(time_t gc_at); +extern void key_schedule_gc_links(void); +extern void key_gc_keytype(struct key_type *ktype); extern int key_task_permission(const key_ref_t key_ref, const struct cred *cred, @@ -155,20 +176,11 @@ extern int key_task_permission(const key_ref_t key_ref, /* * Check to see whether permission is granted to use a key in the desired way. */ -static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) +static inline int key_permission(const key_ref_t key_ref, unsigned perm) { return key_task_permission(key_ref, current_cred(), perm); } -/* required permissions */ -#define KEY_VIEW 0x01 /* require permission to view attributes */ -#define KEY_READ 0x02 /* require permission to read content */ -#define KEY_WRITE 0x04 /* require permission to update / modify */ -#define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ -#define KEY_LINK 0x10 /* require permission to link */ -#define KEY_SETATTR 0x20 /* require permission to change attributes */ -#define KEY_ALL 0x3f /* all the above permissions */ - /* * Authorisation record for request_key(). */ @@ -190,6 +202,17 @@ extern struct key *request_key_auth_new(struct key *target, extern struct key *key_get_instantiation_authkey(key_serial_t target_id); /* + * Determine whether a key is dead. + */ +static inline bool key_is_dead(const struct key *key, time_t limit) +{ + return + key->flags & ((1 << KEY_FLAG_DEAD) | + (1 << KEY_FLAG_INVALIDATED)) || + (key->expiry > 0 && key->expiry <= limit); +} + +/* * keyctl() functions */ extern long keyctl_get_keyring_ID(key_serial_t, int); @@ -214,6 +237,24 @@ extern long keyctl_assume_authority(key_serial_t); extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, size_t buflen); extern long keyctl_session_to_parent(void); +extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t); +extern long keyctl_instantiate_key_iov(key_serial_t, + const struct iovec __user *, + unsigned, key_serial_t); +extern long keyctl_invalidate_key(key_serial_t); + +extern long keyctl_instantiate_key_common(key_serial_t, + const struct iovec *, + unsigned, size_t, key_serial_t); +#ifdef CONFIG_PERSISTENT_KEYRINGS +extern long keyctl_get_persistent(uid_t, key_serial_t); +extern unsigned persistent_keyring_expiry; +#else +static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring) +{ + return -EOPNOTSUPP; +} +#endif /* * Debugging key validation diff --git a/security/keys/key.c b/security/keys/key.c index 1c2d43dc510..2048a110e7f 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -18,10 +18,9 @@ #include <linux/workqueue.h> #include <linux/random.h> #include <linux/err.h> -#include <linux/user_namespace.h> #include "internal.h" -static struct kmem_cache *key_jar; +struct kmem_cache *key_jar; struct rb_root key_serial_tree; /* tree of keys indexed by serial */ DEFINE_SPINLOCK(key_serial_lock); @@ -36,17 +35,9 @@ unsigned int key_quota_maxbytes = 20000; /* general key space quota */ static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); -static void key_cleanup(struct work_struct *work); -static DECLARE_WORK(key_cleanup_task, key_cleanup); - /* We serialise key instantiation and link */ DEFINE_MUTEX(key_construction_mutex); -/* Any key who's type gets unegistered will be re-typed to this */ -static struct key_type key_type_dead = { - .name = "dead", -}; - #ifdef KEY_DEBUGGING void __key_check(const struct key *key) { @@ -60,7 +51,7 @@ void __key_check(const struct key *key) * Get the key quota record for a user, allocating a new record if one doesn't * already exist. */ -struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns) +struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent = NULL; @@ -75,13 +66,9 @@ try_again: parent = *p; user = rb_entry(parent, struct key_user, node); - if (uid < user->uid) - p = &(*p)->rb_left; - else if (uid > user->uid) - p = &(*p)->rb_right; - else if (user_ns < user->user_ns) + if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; - else if (user_ns > user->user_ns) + else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; @@ -110,7 +97,6 @@ try_again: atomic_set(&candidate->nkeys, 0); atomic_set(&candidate->nikeys, 0); candidate->uid = uid; - candidate->user_ns = get_user_ns(user_ns); candidate->qnkeys = 0; candidate->qnbytes = 0; spin_lock_init(&candidate->lock); @@ -139,7 +125,6 @@ void key_user_put(struct key_user *user) if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { rb_erase(&user->node, &key_user_tree); spin_unlock(&key_user_lock); - put_user_ns(user->user_ns); kfree(user); } @@ -237,7 +222,7 @@ serial_exists: * key_alloc() calls don't race with module unloading. */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, const struct cred *cred, + kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; @@ -249,20 +234,28 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!desc || !*desc) goto error; - desclen = strlen(desc) + 1; - quotalen = desclen + type->def_datalen; + if (type->vet_description) { + ret = type->vet_description(desc); + if (ret < 0) { + key = ERR_PTR(ret); + goto error; + } + } + + desclen = strlen(desc); + quotalen = desclen + 1 + type->def_datalen; /* get hold of the key tracking for this user */ - user = key_user_lookup(uid, cred->user->user_ns); + user = key_user_lookup(uid); if (!user) goto no_memory_1; /* check that the user's quota permits allocation of another key and * its description */ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { - unsigned maxkeys = (uid == 0) ? + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&user->lock); @@ -279,34 +272,32 @@ struct key *key_alloc(struct key_type *type, const char *desc, } /* allocate and initialise the key and its description */ - key = kmem_cache_alloc(key_jar, GFP_KERNEL); + key = kmem_cache_zalloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; if (desc) { - key->description = kmemdup(desc, desclen, GFP_KERNEL); + key->index_key.desc_len = desclen; + key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->description) goto no_memory_3; } atomic_set(&key->usage, 1); init_rwsem(&key->sem); - key->type = type; + lockdep_set_class(&key->sem, &type->lock_class); + key->index_key.type = type; key->user = user; key->quotalen = quotalen; key->datalen = type->def_datalen; key->uid = uid; key->gid = gid; key->perm = perm; - key->flags = 0; - key->expiry = 0; - key->payload.data = NULL; - key->security = NULL; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; - - memset(&key->type_data, 0, sizeof(key->type_data)); + if (flags & KEY_ALLOC_TRUSTED) + key->flags |= 1 << KEY_FLAG_TRUSTED; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC; @@ -379,7 +370,7 @@ int key_payload_reserve(struct key *key, size_t datalen) /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxbytes = (key->user->uid == 0) ? + unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&key->user->lock); @@ -411,11 +402,10 @@ EXPORT_SYMBOL(key_payload_reserve); * key_construction_mutex. */ static int __key_instantiate_and_link(struct key *key, - const void *data, - size_t datalen, + struct key_preparsed_payload *prep, struct key *keyring, struct key *authkey, - unsigned long *_prealloc) + struct assoc_array_edit **_edit) { int ret, awaken; @@ -430,7 +420,7 @@ static int __key_instantiate_and_link(struct key *key, /* can't instantiate twice */ if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* instantiate the key */ - ret = key->type->instantiate(key, data, datalen); + ret = key->type->instantiate(key, prep); if (ret == 0) { /* mark the key as being instantiated */ @@ -442,7 +432,7 @@ static int __key_instantiate_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring) - __key_link(keyring, key, _prealloc); + __key_link(key, _edit); /* disable the authorisation key */ if (authkey) @@ -481,52 +471,68 @@ int key_instantiate_and_link(struct key *key, struct key *keyring, struct key *authkey) { - unsigned long prealloc; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; int ret; + memset(&prep, 0, sizeof(prep)); + prep.data = data; + prep.datalen = datalen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; + } + if (keyring) { - ret = __key_link_begin(keyring, key->type, key->description, - &prealloc); + ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret < 0) - return ret; + goto error_free_preparse; } - ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey, - &prealloc); + ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); if (keyring) - __key_link_end(keyring, key->type, prealloc); + __key_link_end(keyring, &key->index_key, edit); +error_free_preparse: + if (key->type->preparse) + key->type->free_preparse(&prep); +error: return ret; } EXPORT_SYMBOL(key_instantiate_and_link); /** - * key_negate_and_link - Negatively instantiate a key and link it into the keyring. + * key_reject_and_link - Negatively instantiate a key and link it into the keyring. * @key: The key to instantiate. * @timeout: The timeout on the negative key. + * @error: The error to return when the key is hit. * @keyring: Keyring to create a link in on success (or NULL). * @authkey: The authorisation token permitting instantiation. * * Negatively instantiate a key that's in the uninstantiated state and, if - * successful, set its timeout and link it in to the destination keyring if one - * is supplied. The key and any links to the key will be automatically garbage - * collected after the timeout expires. + * successful, set its timeout and stored error and link it in to the + * destination keyring if one is supplied. The key and any links to the key + * will be automatically garbage collected after the timeout expires. * * Negative keys are used to rate limit repeated request_key() calls by causing - * them to return -ENOKEY until the negative key expires. + * them to return the stored error code (typically ENOKEY) until the negative + * key expires. * * If successful, 0 is returned, the authorisation token is revoked and anyone * waiting for the key is woken up. If the key was already instantiated, * -EBUSY will be returned. */ -int key_negate_and_link(struct key *key, +int key_reject_and_link(struct key *key, unsigned timeout, + unsigned error, struct key *keyring, struct key *authkey) { - unsigned long prealloc; + struct assoc_array_edit *edit; struct timespec now; int ret, awaken, link_ret = 0; @@ -537,8 +543,7 @@ int key_negate_and_link(struct key *key, ret = -EBUSY; if (keyring) - link_ret = __key_link_begin(keyring, key->type, - key->description, &prealloc); + link_ret = __key_link_begin(keyring, &key->index_key, &edit); mutex_lock(&key_construction_mutex); @@ -546,6 +551,8 @@ int key_negate_and_link(struct key *key, if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); + key->type_data.reject_error = -error; + smp_wmb(); set_bit(KEY_FLAG_NEGATIVE, &key->flags); set_bit(KEY_FLAG_INSTANTIATED, &key->flags); now = current_kernel_time(); @@ -559,7 +566,7 @@ int key_negate_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring && link_ret == 0) - __key_link(keyring, key, &prealloc); + __key_link(key, &edit); /* disable the authorisation key */ if (authkey) @@ -569,7 +576,7 @@ int key_negate_and_link(struct key *key, mutex_unlock(&key_construction_mutex); if (keyring) - __key_link_end(keyring, key->type, prealloc); + __key_link_end(keyring, &key->index_key, edit); /* wake up anyone waiting for a key to be constructed */ if (awaken) @@ -577,73 +584,7 @@ int key_negate_and_link(struct key *key, return ret == 0 ? link_ret : ret; } - -EXPORT_SYMBOL(key_negate_and_link); - -/* - * Garbage collect keys in process context so that we don't have to disable - * interrupts all over the place. - * - * key_put() schedules this rather than trying to do the cleanup itself, which - * means key_put() doesn't have to sleep. - */ -static void key_cleanup(struct work_struct *work) -{ - struct rb_node *_n; - struct key *key; - -go_again: - /* look for a dead key in the tree */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (atomic_read(&key->usage) == 0) - goto found_dead_key; - } - - spin_unlock(&key_serial_lock); - return; - -found_dead_key: - /* we found a dead key - once we've removed it from the tree, we can - * drop the lock */ - rb_erase(&key->serial_node, &key_serial_tree); - spin_unlock(&key_serial_lock); - - key_check(key); - - security_key_free(key); - - /* deal with the user's key tracking and quota */ - if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - spin_lock(&key->user->lock); - key->user->qnkeys--; - key->user->qnbytes -= key->quotalen; - spin_unlock(&key->user->lock); - } - - atomic_dec(&key->user->nkeys); - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) - atomic_dec(&key->user->nikeys); - - key_user_put(key->user); - - /* now throw away the key memory */ - if (key->type->destroy) - key->type->destroy(key); - - kfree(key->description); - -#ifdef KEY_DEBUGGING - key->magic = KEY_DEBUG_MAGIC_X; -#endif - kmem_cache_free(key_jar, key); - - /* there may, of course, be more than one key to destroy */ - goto go_again; -} +EXPORT_SYMBOL(key_reject_and_link); /** * key_put - Discard a reference to a key. @@ -659,7 +600,7 @@ void key_put(struct key *key) key_check(key); if (atomic_dec_and_test(&key->usage)) - schedule_work(&key_cleanup_task); + schedule_work(&key_gc_work); } } EXPORT_SYMBOL(key_put); @@ -699,7 +640,7 @@ found: /* this races with key_put(), but that doesn't matter since key_put() * doesn't actually change the key */ - atomic_inc(&key->usage); + __key_get(key); error: spin_unlock(&key_serial_lock); @@ -732,6 +673,26 @@ found_kernel_type: return ktype; } +void key_set_timeout(struct key *key, unsigned timeout) +{ + struct timespec now; + time_t expiry = 0; + + /* make the changes with the locks held to prevent races */ + down_write(&key->sem); + + if (timeout > 0) { + now = current_kernel_time(); + expiry = now.tv_sec + timeout; + } + + key->expiry = expiry; + key_schedule_gc(key->expiry + key_gc_delay); + + up_write(&key->sem); +} +EXPORT_SYMBOL_GPL(key_set_timeout); + /* * Unlock a key type locked by key_type_lookup(). */ @@ -747,13 +708,13 @@ void key_type_put(struct key_type *ktype) * if we get an error. */ static inline key_ref_t __key_update(key_ref_t key_ref, - const void *payload, size_t plen) + struct key_preparsed_payload *prep) { struct key *key = key_ref_to_ptr(key_ref); int ret; /* need write permission on the key to update it */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; @@ -763,7 +724,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref, down_write(&key->sem); - ret = key->type->update(key, payload, plen); + ret = key->type->update(key, prep); if (ret == 0) /* updating a negative key instantiates it */ clear_bit(KEY_FLAG_NEGATIVE, &key->flags); @@ -814,24 +775,28 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_perm_t perm, unsigned long flags) { - unsigned long prealloc; + struct keyring_index_key index_key = { + .description = description, + }; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; const struct cred *cred = current_cred(); - struct key_type *ktype; struct key *keyring, *key = NULL; key_ref_t key_ref; int ret; /* look up the key type to see if it's one of the registered kernel * types */ - ktype = key_type_lookup(type); - if (IS_ERR(ktype)) { + index_key.type = key_type_lookup(type); + if (IS_ERR(index_key.type)) { key_ref = ERR_PTR(-ENODEV); goto error; } key_ref = ERR_PTR(-EINVAL); - if (!ktype->match || !ktype->instantiate) - goto error_2; + if (!index_key.type->match || !index_key.type->instantiate || + (!index_key.description && !index_key.type->preparse)) + goto error_put_type; keyring = key_ref_to_ptr(keyring_ref); @@ -839,78 +804,105 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_ref = ERR_PTR(-ENOTDIR); if (keyring->type != &key_type_keyring) - goto error_2; + goto error_put_type; + + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = index_key.type->def_datalen; + prep.trusted = flags & KEY_ALLOC_TRUSTED; + if (index_key.type->preparse) { + ret = index_key.type->preparse(&prep); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_put_type; + } + if (!index_key.description) + index_key.description = prep.description; + key_ref = ERR_PTR(-EINVAL); + if (!index_key.description) + goto error_free_prep; + } + index_key.desc_len = strlen(index_key.description); - ret = __key_link_begin(keyring, ktype, description, &prealloc); - if (ret < 0) - goto error_2; + key_ref = ERR_PTR(-EPERM); + if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) + goto error_free_prep; + flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; + + ret = __key_link_begin(keyring, &index_key, &edit); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_free_prep; + } /* if we're going to allocate a new key, we're going to have * to modify the keyring */ - ret = key_permission(keyring_ref, KEY_WRITE); + ret = key_permission(keyring_ref, KEY_NEED_WRITE); if (ret < 0) { key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } /* if it's possible to update this type of key, search for an existing * key of the same type and description in the destination keyring and * update that instead if possible */ - if (ktype->update) { - key_ref = __keyring_search_one(keyring_ref, ktype, description, - 0); - if (!IS_ERR(key_ref)) + if (index_key.type->update) { + key_ref = find_key_to_update(keyring_ref, &index_key); + if (key_ref) goto found_matching_key; } /* if the client doesn't provide, decide on the permissions we want */ if (perm == KEY_PERM_UNDEF) { perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; - perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; + perm |= KEY_USR_VIEW; - if (ktype->read) - perm |= KEY_POS_READ | KEY_USR_READ; + if (index_key.type->read) + perm |= KEY_POS_READ; - if (ktype == &key_type_keyring || ktype->update) - perm |= KEY_USR_WRITE; + if (index_key.type == &key_type_keyring || + index_key.type->update) + perm |= KEY_POS_WRITE; } /* allocate a new key */ - key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, - perm, flags); + key = key_alloc(index_key.type, index_key.description, + cred->fsuid, cred->fsgid, cred, perm, flags); if (IS_ERR(key)) { key_ref = ERR_CAST(key); - goto error_3; + goto error_link_end; } /* instantiate it and link it into the target keyring */ - ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL, - &prealloc); + ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); if (ret < 0) { key_put(key); key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); - error_3: - __key_link_end(keyring, ktype, prealloc); - error_2: - key_type_put(ktype); - error: +error_link_end: + __key_link_end(keyring, &index_key, edit); +error_free_prep: + if (index_key.type->preparse) + index_key.type->free_preparse(&prep); +error_put_type: + key_type_put(index_key.type); +error: return key_ref; found_matching_key: /* we found a matching key, so we're going to try to update it * - we can drop the locks first as we have the key pinned */ - __key_link_end(keyring, ktype, prealloc); - key_type_put(ktype); + __key_link_end(keyring, &index_key, edit); - key_ref = __key_update(key_ref, payload, plen); - goto error; + key_ref = __key_update(key_ref, &prep); + goto error_free_prep; } EXPORT_SYMBOL(key_create_or_update); @@ -929,30 +921,44 @@ EXPORT_SYMBOL(key_create_or_update); */ int key_update(key_ref_t key_ref, const void *payload, size_t plen) { + struct key_preparsed_payload prep; struct key *key = key_ref_to_ptr(key_ref); int ret; key_check(key); /* the key must be writable */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; /* attempt to update it if supported */ ret = -EOPNOTSUPP; - if (key->type->update) { - down_write(&key->sem); - - ret = key->type->update(key, payload, plen); - if (ret == 0) - /* updating a negative key instantiates it */ - clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + if (!key->type->update) + goto error; - up_write(&key->sem); + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; } - error: + down_write(&key->sem); + + ret = key->type->update(key, &prep); + if (ret == 0) + /* updating a negative key instantiates it */ + clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + + up_write(&key->sem); + + if (key->type->preparse) + key->type->free_preparse(&prep); +error: return ret; } EXPORT_SYMBOL(key_update); @@ -996,6 +1002,28 @@ void key_revoke(struct key *key) EXPORT_SYMBOL(key_revoke); /** + * key_invalidate - Invalidate a key. + * @key: The key to be invalidated. + * + * Mark a key as being invalidated and have it cleaned up immediately. The key + * is ignored by all searches and other operations from this point. + */ +void key_invalidate(struct key *key) +{ + kenter("%d", key_serial(key)); + + key_check(key); + + if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + down_write_nested(&key->sem, 1); + if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) + key_schedule_gc_links(); + up_write(&key->sem); + } +} +EXPORT_SYMBOL(key_invalidate); + +/** * register_key_type - Register a type of key. * @ktype: The new key type. * @@ -1008,6 +1036,8 @@ int register_key_type(struct key_type *ktype) struct key_type *p; int ret; + memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); + ret = -EEXIST; down_write(&key_types_sem); @@ -1019,6 +1049,8 @@ int register_key_type(struct key_type *ktype) /* store the type */ list_add(&ktype->link, &key_types_list); + + pr_notice("Key type %s registered\n", ktype->name); ret = 0; out: @@ -1037,49 +1069,12 @@ EXPORT_SYMBOL(register_key_type); */ void unregister_key_type(struct key_type *ktype) { - struct rb_node *_n; - struct key *key; - down_write(&key_types_sem); - - /* withdraw the key type */ list_del_init(&ktype->link); - - /* mark all the keys of this type dead */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) { - key->type = &key_type_dead; - set_bit(KEY_FLAG_DEAD, &key->flags); - } - } - - spin_unlock(&key_serial_lock); - - /* make sure everyone revalidates their keys */ - synchronize_rcu(); - - /* we should now be able to destroy the payloads of all the keys of - * this type with impunity */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) { - if (ktype->destroy) - ktype->destroy(key); - memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); - } - } - - spin_unlock(&key_serial_lock); - up_write(&key_types_sem); - - key_schedule_gc(0); + downgrade_write(&key_types_sem); + key_gc_keytype(ktype); + pr_notice("Key type %s unregistered\n", ktype->name); + up_read(&key_types_sem); } EXPORT_SYMBOL(unregister_key_type); @@ -1096,6 +1091,7 @@ void __init key_init(void) list_add_tail(&key_type_keyring.link, &key_types_list); list_add_tail(&key_type_dead.link, &key_types_list); list_add_tail(&key_type_user.link, &key_types_list); + list_add_tail(&key_type_logon.link, &key_types_list); /* record the root user tracking */ rb_link_node(&root_key_user.node, diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 31a0fd8189f..cd5bd0cef25 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -14,6 +14,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/syscalls.h> +#include <linux/key.h> #include <linux/keyctl.h> #include <linux/fs.h> #include <linux/capability.h> @@ -21,6 +22,7 @@ #include <linux/err.h> #include <linux/vmalloc.h> #include <linux/security.h> +#include <linux/uio.h> #include <asm/uaccess.h> #include "internal.h" @@ -45,6 +47,9 @@ static int key_get_type_from_user(char *type, * Extract the description of a new key from userspace and either add it as a * new key to the specified keyring or update a matching key in that keyring. * + * If the description is NULL or an empty string, the key type is asked to + * generate one from the payload. + * * The keyring must be writable so that we can attach the key to it. * * If successful, the new key's serial number is returned, otherwise an error @@ -71,10 +76,17 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type, if (ret < 0) goto error; - description = strndup_user(_description, PAGE_SIZE); - if (IS_ERR(description)) { - ret = PTR_ERR(description); - goto error; + description = NULL; + if (_description) { + description = strndup_user(_description, PAGE_SIZE); + if (IS_ERR(description)) { + ret = PTR_ERR(description); + goto error; + } + if (!*description) { + kfree(description); + description = NULL; + } } /* pull the payload in if one was supplied */ @@ -83,7 +95,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type, vm = false; if (_payload) { ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); + payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN); if (!payload) { if (plen <= PAGE_SIZE) goto error2; @@ -99,7 +111,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type, } /* find the target keyring (which must be writable) */ - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error3; @@ -183,7 +195,7 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type, dest_ref = NULL; if (destringid) { dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, - KEY_WRITE); + KEY_NEED_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -206,8 +218,14 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type, goto error5; } + /* wait for the key to finish being constructed */ + ret = wait_for_key_construction(key, 1); + if (ret < 0) + goto error6; + ret = key->serial; +error6: key_put(key); error5: key_type_put(ktype); @@ -235,7 +253,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create) long ret; lflags = create ? KEY_LOOKUP_CREATE : 0; - key_ref = lookup_user_key(id, lflags, KEY_SEARCH); + key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -316,7 +334,7 @@ long keyctl_update_key(key_serial_t id, } /* find the target key (which must be writable) */ - key_ref = lookup_user_key(id, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -347,12 +365,12 @@ long keyctl_revoke_key(key_serial_t id) key_ref_t key_ref; long ret; - key_ref = lookup_user_key(id, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); if (ret != -EACCES) goto error; - key_ref = lookup_user_key(id, 0, KEY_SETATTR); + key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -368,6 +386,37 @@ error: } /* + * Invalidate a key. + * + * The key must be grant the caller Invalidate permission for this to work. + * The key and any links to the key will be automatically garbage collected + * immediately. + * + * If successful, 0 is returned. + */ +long keyctl_invalidate_key(key_serial_t id) +{ + key_ref_t key_ref; + long ret; + + kenter("%d", id); + + key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } + + key_invalidate(key_ref_to_ptr(key_ref)); + ret = 0; + + key_ref_put(key_ref); +error: + kleave(" = %ld", ret); + return ret; +} + +/* * Clear the specified keyring, creating an empty process keyring if one of the * special keyring IDs is used. * @@ -379,14 +428,27 @@ long keyctl_keyring_clear(key_serial_t ringid) key_ref_t keyring_ref; long ret; - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); + + /* Root is permitted to invalidate certain special keyrings */ + if (capable(CAP_SYS_ADMIN)) { + keyring_ref = lookup_user_key(ringid, 0, 0); + if (IS_ERR(keyring_ref)) + goto error; + if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, + &key_ref_to_ptr(keyring_ref)->flags)) + goto clear; + goto error_put; + } + goto error; } +clear: ret = keyring_clear(key_ref_to_ptr(keyring_ref)); - +error_put: key_ref_put(keyring_ref); error: return ret; @@ -408,13 +470,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; } - key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK); + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -443,7 +505,7 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; @@ -486,7 +548,7 @@ long keyctl_describe_key(key_serial_t keyid, char *tmpbuf; long ret; - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); if (IS_ERR(key_ref)) { /* viewing a key under construction is permitted if we have the * authorisation token handy */ @@ -518,8 +580,8 @@ okay: ret = snprintf(tmpbuf, PAGE_SIZE - 1, "%s;%d;%d;%08x;%s", key->type->name, - key->uid, - key->gid, + from_kuid_munged(current_user_ns(), key->uid), + from_kgid_munged(current_user_ns(), key->gid), key->perm, key->description ?: ""); @@ -577,7 +639,7 @@ long keyctl_keyring_search(key_serial_t ringid, } /* get the keyring at which to begin the search */ - keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH); + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error2; @@ -587,7 +649,7 @@ long keyctl_keyring_search(key_serial_t ringid, dest_ref = NULL; if (destringid) { dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, - KEY_WRITE); + KEY_NEED_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -614,7 +676,7 @@ long keyctl_keyring_search(key_serial_t ringid, /* link the resulting key to the destination keyring if we can */ if (dest_ref) { - ret = key_permission(key_ref, KEY_LINK); + ret = key_permission(key_ref, KEY_NEED_LINK); if (ret < 0) goto error6; @@ -665,7 +727,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) key = key_ref_to_ptr(key_ref); /* see if we can read it directly */ - ret = key_permission(key_ref, KEY_READ); + ret = key_permission(key_ref, KEY_NEED_READ); if (ret == 0) goto can_read_key; if (ret != -EACCES) @@ -715,19 +777,29 @@ error: * * If successful, 0 will be returned. */ -long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) +long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) { struct key_user *newowner, *zapowner = NULL; struct key *key; key_ref_t key_ref; long ret; + kuid_t uid; + kgid_t gid; + + uid = make_kuid(current_user_ns(), user); + gid = make_kgid(current_user_ns(), group); + ret = -EINVAL; + if ((user != (uid_t) -1) && !uid_valid(uid)) + goto error; + if ((group != (gid_t) -1) && !gid_valid(gid)) + goto error; ret = 0; - if (uid == (uid_t) -1 && gid == (gid_t) -1) + if (user == (uid_t) -1 && group == (gid_t) -1) goto error; key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -741,27 +813,27 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) if (!capable(CAP_SYS_ADMIN)) { /* only the sysadmin can chown a key to some other UID */ - if (uid != (uid_t) -1 && key->uid != uid) + if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) goto error_put; /* only the sysadmin can set the key's GID to a group other * than one of those that the current process subscribes to */ - if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) + if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) goto error_put; } /* change the UID */ - if (uid != (uid_t) -1 && uid != key->uid) { + if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { ret = -ENOMEM; - newowner = key_user_lookup(uid, current_user_ns()); + newowner = key_user_lookup(uid); if (!newowner) goto error_put; /* transfer the quota burden to the new user */ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxkeys = (uid == 0) ? + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&newowner->lock); @@ -795,7 +867,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) } /* change the GID */ - if (gid != (gid_t) -1) + if (group != (gid_t) -1) key->gid = gid; ret = 0; @@ -833,7 +905,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) goto error; key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -846,7 +918,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) down_write(&key->sem); /* if we're not the sysadmin, we can only change a key that we own */ - if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) { + if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { key->perm = perm; ret = 0; } @@ -875,7 +947,7 @@ static long get_instantiation_keyring(key_serial_t ringid, /* if a specific keyring is nominated by ID, then use that */ if (ringid > 0) { - dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); + dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(dkref)) return PTR_ERR(dkref); *_dest_keyring = key_ref_to_ptr(dkref); @@ -913,6 +985,21 @@ static int keyctl_change_reqkey_auth(struct key *key) } /* + * Copy the iovec data from userspace + */ +static long copy_from_user_iovec(void *buffer, const struct iovec *iov, + unsigned ioc) +{ + for (; ioc > 0; ioc--) { + if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0) + return -EFAULT; + buffer += iov->iov_len; + iov++; + } + return 0; +} + +/* * Instantiate a key with the specified payload and link the key into the * destination keyring if one is given. * @@ -921,10 +1008,11 @@ static int keyctl_change_reqkey_auth(struct key *key) * * If successful, 0 will be returned. */ -long keyctl_instantiate_key(key_serial_t id, - const void __user *_payload, - size_t plen, - key_serial_t ringid) +long keyctl_instantiate_key_common(key_serial_t id, + const struct iovec *payload_iov, + unsigned ioc, + size_t plen, + key_serial_t ringid) { const struct cred *cred = current_cred(); struct request_key_auth *rka; @@ -953,7 +1041,7 @@ long keyctl_instantiate_key(key_serial_t id, /* pull the payload in if one was supplied */ payload = NULL; - if (_payload) { + if (payload_iov) { ret = -ENOMEM; payload = kmalloc(plen, GFP_KERNEL); if (!payload) { @@ -965,8 +1053,8 @@ long keyctl_instantiate_key(key_serial_t id, goto error; } - ret = -EFAULT; - if (copy_from_user(payload, _payload, plen) != 0) + ret = copy_from_user_iovec(payload, payload_iov, ioc); + if (ret < 0) goto error2; } @@ -997,6 +1085,72 @@ error: } /* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key(key_serial_t id, + const void __user *_payload, + size_t plen, + key_serial_t ringid) +{ + if (_payload && plen) { + struct iovec iov[1] = { + [0].iov_base = (void __user *)_payload, + [0].iov_len = plen + }; + + return keyctl_instantiate_key_common(id, iov, 1, plen, ringid); + } + + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* + * Instantiate a key with the specified multipart payload and link the key into + * the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key_iov(key_serial_t id, + const struct iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + long ret; + + if (!_payload_iov || !ioc) + goto no_payload; + + ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), iovstack, &iov); + if (ret < 0) + goto err; + if (ret == 0) + goto no_payload_free; + + ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); +err: + if (iov != iovstack) + kfree(iov); + return ret; + +no_payload_free: + if (iov != iovstack) + kfree(iov); +no_payload: + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* * Negatively instantiate the key with the given timeout (in seconds) and link * the key into the destination keyring if one is given. * @@ -1013,12 +1167,42 @@ error: */ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) { + return keyctl_reject_key(id, timeout, ENOKEY, ringid); +} + +/* + * Negatively instantiate the key with the given timeout (in seconds) and error + * code and link the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * The key and any links to the key will be automatically garbage collected + * after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return the specified error code until the negative key expires. + * + * If successful, 0 will be returned. + */ +long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, + key_serial_t ringid) +{ const struct cred *cred = current_cred(); struct request_key_auth *rka; struct key *instkey, *dest_keyring; long ret; - kenter("%d,%u,%d", id, timeout, ringid); + kenter("%d,%u,%u,%d", id, timeout, error, ringid); + + /* must be a valid error code and mustn't be a kernel special */ + if (error <= 0 || + error >= MAX_ERRNO || + error == ERESTARTSYS || + error == ERESTARTNOINTR || + error == ERESTARTNOHAND || + error == ERESTART_RESTARTBLOCK) + return -EINVAL; /* the appropriate instantiation authorisation key must have been * assumed before calling this */ @@ -1038,7 +1222,7 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) goto error; /* instantiate the key and link it into a keyring */ - ret = key_negate_and_link(rka->target_key, timeout, + ret = key_reject_and_link(rka->target_key, timeout, error, dest_keyring, instkey); key_put(dest_keyring); @@ -1126,14 +1310,12 @@ error: */ long keyctl_set_timeout(key_serial_t id, unsigned timeout) { - struct timespec now; struct key *key, *instkey; key_ref_t key_ref; - time_t expiry; long ret; key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, - KEY_SETATTR); + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { /* setting the timeout on a key under construction is permitted * if we have the authorisation token handy */ @@ -1155,20 +1337,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout) okay: key = key_ref_to_ptr(key_ref); - - /* make the changes with the locks held to prevent races */ - down_write(&key->sem); - - expiry = 0; - if (timeout > 0) { - now = current_kernel_time(); - expiry = now.tv_sec + timeout; - } - - key->expiry = expiry; - key_schedule_gc(key->expiry + key_gc_delay); - - up_write(&key->sem); + key_set_timeout(key, timeout); key_put(key); ret = 0; @@ -1249,7 +1418,7 @@ long keyctl_get_security(key_serial_t keyid, char *context; long ret; - key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); if (IS_ERR(key_ref)) { if (PTR_ERR(key_ref) != -EACCES) return PTR_ERR(key_ref); @@ -1306,103 +1475,93 @@ long keyctl_get_security(key_serial_t keyid, */ long keyctl_session_to_parent(void) { -#ifdef TIF_NOTIFY_RESUME struct task_struct *me, *parent; const struct cred *mycred, *pcred; - struct cred *cred, *oldcred; + struct callback_head *newwork, *oldwork; key_ref_t keyring_r; + struct cred *cred; int ret; - keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK); + keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK); if (IS_ERR(keyring_r)) return PTR_ERR(keyring_r); + ret = -ENOMEM; + /* our parent is going to need a new cred struct, a new tgcred struct * and new security data, so we allocate them here to prevent ENOMEM in * our parent */ - ret = -ENOMEM; cred = cred_alloc_blank(); if (!cred) goto error_keyring; + newwork = &cred->rcu; - cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r); + cred->session_keyring = key_ref_to_ptr(keyring_r); keyring_r = NULL; + init_task_work(newwork, key_change_session_keyring); me = current; rcu_read_lock(); write_lock_irq(&tasklist_lock); - parent = me->real_parent; ret = -EPERM; + oldwork = NULL; + parent = me->real_parent; /* the parent mustn't be init and mustn't be a kernel thread */ if (parent->pid <= 1 || !parent->mm) - goto not_permitted; + goto unlock; /* the parent must be single threaded */ if (!thread_group_empty(parent)) - goto not_permitted; + goto unlock; /* the parent and the child must have different session keyrings or * there's no point */ mycred = current_cred(); pcred = __task_cred(parent); if (mycred == pcred || - mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) - goto already_same; + mycred->session_keyring == pcred->session_keyring) { + ret = 0; + goto unlock; + } /* the parent must have the same effective ownership and mustn't be * SUID/SGID */ - if (pcred->uid != mycred->euid || - pcred->euid != mycred->euid || - pcred->suid != mycred->euid || - pcred->gid != mycred->egid || - pcred->egid != mycred->egid || - pcred->sgid != mycred->egid) - goto not_permitted; + if (!uid_eq(pcred->uid, mycred->euid) || + !uid_eq(pcred->euid, mycred->euid) || + !uid_eq(pcred->suid, mycred->euid) || + !gid_eq(pcred->gid, mycred->egid) || + !gid_eq(pcred->egid, mycred->egid) || + !gid_eq(pcred->sgid, mycred->egid)) + goto unlock; /* the keyrings must have the same UID */ - if ((pcred->tgcred->session_keyring && - pcred->tgcred->session_keyring->uid != mycred->euid) || - mycred->tgcred->session_keyring->uid != mycred->euid) - goto not_permitted; + if ((pcred->session_keyring && + !uid_eq(pcred->session_keyring->uid, mycred->euid)) || + !uid_eq(mycred->session_keyring->uid, mycred->euid)) + goto unlock; - /* if there's an already pending keyring replacement, then we replace - * that */ - oldcred = parent->replacement_session_keyring; + /* cancel an already pending keyring replacement */ + oldwork = task_work_cancel(parent, key_change_session_keyring); /* the replacement session keyring is applied just prior to userspace * restarting */ - parent->replacement_session_keyring = cred; - cred = NULL; - set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME); - + ret = task_work_add(parent, newwork, true); + if (!ret) + newwork = NULL; +unlock: write_unlock_irq(&tasklist_lock); rcu_read_unlock(); - if (oldcred) - put_cred(oldcred); - return 0; - -already_same: - ret = 0; -not_permitted: - write_unlock_irq(&tasklist_lock); - rcu_read_unlock(); - put_cred(cred); + if (oldwork) + put_cred(container_of(oldwork, struct cred, rcu)); + if (newwork) + put_cred(cred); return ret; error_keyring: key_ref_put(keyring_r); return ret; - -#else /* !TIF_NOTIFY_RESUME */ - /* - * To be removed when TIF_NOTIFY_RESUME has been implemented on - * m68k/xtensa - */ -#warning TIF_NOTIFY_RESUME not implemented - return -EOPNOTSUPP; -#endif /* !TIF_NOTIFY_RESUME */ } /* @@ -1492,6 +1651,25 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, case KEYCTL_SESSION_TO_PARENT: return keyctl_session_to_parent(); + case KEYCTL_REJECT: + return keyctl_reject_key((key_serial_t) arg2, + (unsigned) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INSTANTIATE_IOV: + return keyctl_instantiate_key_iov( + (key_serial_t) arg2, + (const struct iovec __user *) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key((key_serial_t) arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 5620f084ded..9cf2575f0d9 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1,6 +1,6 @@ /* Keyring handling * - * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -17,16 +17,11 @@ #include <linux/seq_file.h> #include <linux/err.h> #include <keys/keyring-type.h> +#include <keys/user-type.h> +#include <linux/assoc_array_priv.h> #include <linux/uaccess.h> #include "internal.h" -#define rcu_dereference_locked_keyring(keyring) \ - (rcu_dereference_protected( \ - (keyring)->payload.subscriptions, \ - rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) - -#define KEY_LINK_FIXQUOTA 1UL - /* * When plumbing the depths of the key tree, this sets a hard limit * set on how deep we're willing to go. @@ -38,6 +33,28 @@ */ #define KEYRING_NAME_HASH_SIZE (1 << 5) +/* + * We mark pointers we pass to the associative array with bit 1 set if + * they're keyrings and clear otherwise. + */ +#define KEYRING_PTR_SUBTYPE 0x2UL + +static inline bool keyring_ptr_is_keyring(const struct assoc_array_ptr *x) +{ + return (unsigned long)x & KEYRING_PTR_SUBTYPE; +} +static inline struct key *keyring_ptr_to_key(const struct assoc_array_ptr *x) +{ + void *object = assoc_array_ptr_to_leaf(x); + return (struct key *)((unsigned long)object & ~KEYRING_PTR_SUBTYPE); +} +static inline void *keyring_key_to_ptr(struct key *key) +{ + if (key->type == &key_type_keyring) + return (void *)((unsigned long)key | KEYRING_PTR_SUBTYPE); + return key; +} + static struct list_head keyring_name_hash[KEYRING_NAME_HASH_SIZE]; static DEFINE_RWLOCK(keyring_name_lock); @@ -57,8 +74,7 @@ static inline unsigned keyring_hash(const char *desc) * operations. */ static int keyring_instantiate(struct key *keyring, - const void *data, size_t datalen); -static int keyring_match(const struct key *keyring, const void *criterion); + struct key_preparsed_payload *prep); static void keyring_revoke(struct key *keyring); static void keyring_destroy(struct key *keyring); static void keyring_describe(const struct key *keyring, struct seq_file *m); @@ -67,9 +83,9 @@ static long keyring_read(const struct key *keyring, struct key_type key_type_keyring = { .name = "keyring", - .def_datalen = sizeof(struct keyring_list), + .def_datalen = 0, .instantiate = keyring_instantiate, - .match = keyring_match, + .match = user_match, .revoke = keyring_revoke, .destroy = keyring_destroy, .describe = keyring_describe, @@ -112,12 +128,13 @@ static void keyring_publish_name(struct key *keyring) * Returns 0 on success, -EINVAL if given any data. */ static int keyring_instantiate(struct key *keyring, - const void *data, size_t datalen) + struct key_preparsed_payload *prep) { int ret; ret = -EINVAL; - if (datalen == 0) { + if (prep->datalen == 0) { + assoc_array_init(&keyring->keys); /* make the keyring available by name if it has one */ keyring_publish_name(keyring); ret = 0; @@ -127,23 +144,235 @@ static int keyring_instantiate(struct key *keyring, } /* - * Match keyrings on their name + * Multiply 64-bits by 32-bits to 96-bits and fold back to 64-bit. Ideally we'd + * fold the carry back too, but that requires inline asm. + */ +static u64 mult_64x32_and_fold(u64 x, u32 y) +{ + u64 hi = (u64)(u32)(x >> 32) * y; + u64 lo = (u64)(u32)(x) * y; + return lo + ((u64)(u32)hi << 32) + (u32)(hi >> 32); +} + +/* + * Hash a key type and description. + */ +static unsigned long hash_key_type_and_desc(const struct keyring_index_key *index_key) +{ + const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP; + const unsigned long fan_mask = ASSOC_ARRAY_FAN_MASK; + const char *description = index_key->description; + unsigned long hash, type; + u32 piece; + u64 acc; + int n, desc_len = index_key->desc_len; + + type = (unsigned long)index_key->type; + + acc = mult_64x32_and_fold(type, desc_len + 13); + acc = mult_64x32_and_fold(acc, 9207); + for (;;) { + n = desc_len; + if (n <= 0) + break; + if (n > 4) + n = 4; + piece = 0; + memcpy(&piece, description, n); + description += n; + desc_len -= n; + acc = mult_64x32_and_fold(acc, piece); + acc = mult_64x32_and_fold(acc, 9207); + } + + /* Fold the hash down to 32 bits if need be. */ + hash = acc; + if (ASSOC_ARRAY_KEY_CHUNK_SIZE == 32) + hash ^= acc >> 32; + + /* Squidge all the keyrings into a separate part of the tree to + * ordinary keys by making sure the lowest level segment in the hash is + * zero for keyrings and non-zero otherwise. + */ + if (index_key->type != &key_type_keyring && (hash & fan_mask) == 0) + return hash | (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1; + if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0) + return (hash + (hash << level_shift)) & ~fan_mask; + return hash; +} + +/* + * Build the next index key chunk. + * + * On 32-bit systems the index key is laid out as: + * + * 0 4 5 9... + * hash desclen typeptr desc[] + * + * On 64-bit systems: + * + * 0 8 9 17... + * hash desclen typeptr desc[] + * + * We return it one word-sized chunk at a time. + */ +static unsigned long keyring_get_key_chunk(const void *data, int level) +{ + const struct keyring_index_key *index_key = data; + unsigned long chunk = 0; + long offset = 0; + int desc_len = index_key->desc_len, n = sizeof(chunk); + + level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; + switch (level) { + case 0: + return hash_key_type_and_desc(index_key); + case 1: + return ((unsigned long)index_key->type << 8) | desc_len; + case 2: + if (desc_len == 0) + return (u8)((unsigned long)index_key->type >> + (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); + n--; + offset = 1; + default: + offset += sizeof(chunk) - 1; + offset += (level - 3) * sizeof(chunk); + if (offset >= desc_len) + return 0; + desc_len -= offset; + if (desc_len > n) + desc_len = n; + offset += desc_len; + do { + chunk <<= 8; + chunk |= ((u8*)index_key->description)[--offset]; + } while (--desc_len > 0); + + if (level == 2) { + chunk <<= 8; + chunk |= (u8)((unsigned long)index_key->type >> + (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); + } + return chunk; + } +} + +static unsigned long keyring_get_object_key_chunk(const void *object, int level) +{ + const struct key *key = keyring_ptr_to_key(object); + return keyring_get_key_chunk(&key->index_key, level); +} + +static bool keyring_compare_object(const void *object, const void *data) +{ + const struct keyring_index_key *index_key = data; + const struct key *key = keyring_ptr_to_key(object); + + return key->index_key.type == index_key->type && + key->index_key.desc_len == index_key->desc_len && + memcmp(key->index_key.description, index_key->description, + index_key->desc_len) == 0; +} + +/* + * Compare the index keys of a pair of objects and determine the bit position + * at which they differ - if they differ. + */ +static int keyring_diff_objects(const void *object, const void *data) +{ + const struct key *key_a = keyring_ptr_to_key(object); + const struct keyring_index_key *a = &key_a->index_key; + const struct keyring_index_key *b = data; + unsigned long seg_a, seg_b; + int level, i; + + level = 0; + seg_a = hash_key_type_and_desc(a); + seg_b = hash_key_type_and_desc(b); + if ((seg_a ^ seg_b) != 0) + goto differ; + + /* The number of bits contributed by the hash is controlled by a + * constant in the assoc_array headers. Everything else thereafter we + * can deal with as being machine word-size dependent. + */ + level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; + seg_a = a->desc_len; + seg_b = b->desc_len; + if ((seg_a ^ seg_b) != 0) + goto differ; + + /* The next bit may not work on big endian */ + level++; + seg_a = (unsigned long)a->type; + seg_b = (unsigned long)b->type; + if ((seg_a ^ seg_b) != 0) + goto differ; + + level += sizeof(unsigned long); + if (a->desc_len == 0) + goto same; + + i = 0; + if (((unsigned long)a->description | (unsigned long)b->description) & + (sizeof(unsigned long) - 1)) { + do { + seg_a = *(unsigned long *)(a->description + i); + seg_b = *(unsigned long *)(b->description + i); + if ((seg_a ^ seg_b) != 0) + goto differ_plus_i; + i += sizeof(unsigned long); + } while (i < (a->desc_len & (sizeof(unsigned long) - 1))); + } + + for (; i < a->desc_len; i++) { + seg_a = *(unsigned char *)(a->description + i); + seg_b = *(unsigned char *)(b->description + i); + if ((seg_a ^ seg_b) != 0) + goto differ_plus_i; + } + +same: + return -1; + +differ_plus_i: + level += i; +differ: + i = level * 8 + __ffs(seg_a ^ seg_b); + return i; +} + +/* + * Free an object after stripping the keyring flag off of the pointer. */ -static int keyring_match(const struct key *keyring, const void *description) +static void keyring_free_object(void *object) { - return keyring->description && - strcmp(keyring->description, description) == 0; + key_put(keyring_ptr_to_key(object)); } /* + * Operations for keyring management by the index-tree routines. + */ +static const struct assoc_array_ops keyring_assoc_array_ops = { + .get_key_chunk = keyring_get_key_chunk, + .get_object_key_chunk = keyring_get_object_key_chunk, + .compare_object = keyring_compare_object, + .diff_objects = keyring_diff_objects, + .free_object = keyring_free_object, +}; + +/* * Clean up a keyring when it is destroyed. Unpublish its name if it had one * and dispose of its data. + * + * The garbage collector detects the final key_put(), removes the keyring from + * the serial number tree and then does RCU synchronisation before coming here, + * so we shouldn't need to worry about code poking around here with the RCU + * readlock held by this time. */ static void keyring_destroy(struct key *keyring) { - struct keyring_list *klist; - int loop; - if (keyring->description) { write_lock(&keyring_name_lock); @@ -154,14 +383,7 @@ static void keyring_destroy(struct key *keyring) write_unlock(&keyring_name_lock); } - klist = rcu_dereference_check(keyring->payload.subscriptions, - rcu_read_lock_held() || - atomic_read(&keyring->usage) == 0); - if (klist) { - for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); - kfree(klist); - } + assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops); } /* @@ -169,90 +391,102 @@ static void keyring_destroy(struct key *keyring) */ static void keyring_describe(const struct key *keyring, struct seq_file *m) { - struct keyring_list *klist; - if (keyring->description) seq_puts(m, keyring->description); else seq_puts(m, "[anon]"); - rcu_read_lock(); - klist = rcu_dereference(keyring->payload.subscriptions); - if (klist) - seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys); - else - seq_puts(m, ": empty"); - rcu_read_unlock(); + if (key_is_instantiated(keyring)) { + if (keyring->keys.nr_leaves_on_tree != 0) + seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree); + else + seq_puts(m, ": empty"); + } +} + +struct keyring_read_iterator_context { + size_t qty; + size_t count; + key_serial_t __user *buffer; +}; + +static int keyring_read_iterator(const void *object, void *data) +{ + struct keyring_read_iterator_context *ctx = data; + const struct key *key = keyring_ptr_to_key(object); + int ret; + + kenter("{%s,%d},,{%zu/%zu}", + key->type->name, key->serial, ctx->count, ctx->qty); + + if (ctx->count >= ctx->qty) + return 1; + + ret = put_user(key->serial, ctx->buffer); + if (ret < 0) + return ret; + ctx->buffer++; + ctx->count += sizeof(key->serial); + return 0; } /* * Read a list of key IDs from the keyring's contents in binary form * - * The keyring's semaphore is read-locked by the caller. + * The keyring's semaphore is read-locked by the caller. This prevents someone + * from modifying it under us - which could cause us to read key IDs multiple + * times. */ static long keyring_read(const struct key *keyring, char __user *buffer, size_t buflen) { - struct keyring_list *klist; - struct key *key; - size_t qty, tmp; - int loop, ret; + struct keyring_read_iterator_context ctx; + unsigned long nr_keys; + int ret; - ret = 0; - klist = rcu_dereference_locked_keyring(keyring); - if (klist) { - /* calculate how much data we could return */ - qty = klist->nkeys * sizeof(key_serial_t); - - if (buffer && buflen > 0) { - if (buflen > qty) - buflen = qty; - - /* copy the IDs of the subscribed keys into the - * buffer */ - ret = -EFAULT; - - for (loop = 0; loop < klist->nkeys; loop++) { - key = klist->keys[loop]; - - tmp = sizeof(key_serial_t); - if (tmp > buflen) - tmp = buflen; - - if (copy_to_user(buffer, - &key->serial, - tmp) != 0) - goto error; - - buflen -= tmp; - if (buflen == 0) - break; - buffer += tmp; - } - } + kenter("{%d},,%zu", key_serial(keyring), buflen); + + if (buflen & (sizeof(key_serial_t) - 1)) + return -EINVAL; + + nr_keys = keyring->keys.nr_leaves_on_tree; + if (nr_keys == 0) + return 0; + + /* Calculate how much data we could return */ + ctx.qty = nr_keys * sizeof(key_serial_t); + + if (!buffer || !buflen) + return ctx.qty; - ret = qty; + if (buflen > ctx.qty) + ctx.qty = buflen; + + /* Copy the IDs of the subscribed keys into the buffer */ + ctx.buffer = (key_serial_t __user *)buffer; + ctx.count = 0; + ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx); + if (ret < 0) { + kleave(" = %d [iterate]", ret); + return ret; } -error: - return ret; + kleave(" = %zu [ok]", ctx.count); + return ctx.count; } /* * Allocate a keyring and link into the destination keyring. */ -struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, - const struct cred *cred, unsigned long flags, - struct key *dest) +struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, + const struct cred *cred, key_perm_t perm, + unsigned long flags, struct key *dest) { struct key *keyring; int ret; keyring = key_alloc(&key_type_keyring, description, - uid, gid, cred, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - flags); - + uid, gid, cred, perm, flags); if (!IS_ERR(keyring)) { ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); if (ret < 0) { @@ -263,202 +497,363 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, return keyring; } +EXPORT_SYMBOL(keyring_alloc); -/** - * keyring_search_aux - Search a keyring tree for a key matching some criteria - * @keyring_ref: A pointer to the keyring with possession indicator. - * @cred: The credentials to use for permissions checks. - * @type: The type of key to search for. - * @description: Parameter for @match. - * @match: Function to rule on whether or not a key is the one required. - * - * Search the supplied keyring tree for a key that matches the criteria given. - * The root keyring and any linked keyrings must grant Search permission to the - * caller to be searchable and keys can only be found if they too grant Search - * to the caller. The possession flag on the root keyring pointer controls use - * of the possessor bits in permissions checking of the entire tree. In - * addition, the LSM gets to forbid keyring searches and key matches. - * - * The search is performed as a breadth-then-depth search up to the prescribed - * limit (KEYRING_SEARCH_MAX_DEPTH). - * - * Keys are matched to the type provided and are then filtered by the match - * function, which is given the description to use in any way it sees fit. The - * match function may use any attributes of a key that it wishes to to - * determine the match. Normally the match function from the key type would be - * used. - * - * RCU is used to prevent the keyring key lists from disappearing without the - * need to take lots of locks. - * - * Returns a pointer to the found key and increments the key usage count if - * successful; -EAGAIN if no matching keys were found, or if expired or revoked - * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the - * specified keyring wasn't a keyring. - * - * In the case of a successful return, the possession attribute from - * @keyring_ref is propagated to the returned key reference. +/* + * Iteration function to consider each key found. */ -key_ref_t keyring_search_aux(key_ref_t keyring_ref, - const struct cred *cred, - struct key_type *type, - const void *description, - key_match_func_t match) +static int keyring_search_iterator(const void *object, void *iterator_data) { - struct { - struct keyring_list *keylist; - int kix; - } stack[KEYRING_SEARCH_MAX_DEPTH]; - - struct keyring_list *keylist; - struct timespec now; - unsigned long possessed, kflags; - struct key *keyring, *key; - key_ref_t key_ref; - long err; - int sp, kix; + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + unsigned long kflags = key->flags; - keyring = key_ref_to_ptr(keyring_ref); - possessed = is_key_possessed(keyring_ref); - key_check(keyring); + kenter("{%d}", key->serial); - /* top keyring must have search permission to begin the search */ - err = key_task_permission(keyring_ref, cred, KEY_SEARCH); - if (err < 0) { - key_ref = ERR_PTR(err); - goto error; + /* ignore keys not of this type */ + if (key->type != ctx->index_key.type) { + kleave(" = 0 [!type]"); + return 0; } - key_ref = ERR_PTR(-ENOTDIR); - if (keyring->type != &key_type_keyring) - goto error; + /* skip invalidated, revoked and expired keys */ + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + ctx->result = ERR_PTR(-EKEYREVOKED); + kleave(" = %d [invrev]", ctx->skipped_ret); + goto skipped; + } - rcu_read_lock(); + if (key->expiry && ctx->now.tv_sec >= key->expiry) { + ctx->result = ERR_PTR(-EKEYEXPIRED); + kleave(" = %d [expire]", ctx->skipped_ret); + goto skipped; + } + } - now = current_kernel_time(); - err = -EAGAIN; - sp = 0; - - /* firstly we should check to see if this top-level keyring is what we - * are looking for */ - key_ref = ERR_PTR(-EAGAIN); - kflags = keyring->flags; - if (keyring->type == type && match(keyring, description)) { - key = keyring; - - /* check it isn't negative and hasn't expired or been - * revoked */ - if (kflags & (1 << KEY_FLAG_REVOKED)) - goto error_2; - if (key->expiry && now.tv_sec >= key->expiry) - goto error_2; - key_ref = ERR_PTR(-ENOKEY); - if (kflags & (1 << KEY_FLAG_NEGATIVE)) - goto error_2; - goto found; + /* keys that don't match */ + if (!ctx->match(key, ctx->match_data)) { + kleave(" = 0 [!match]"); + return 0; } - /* otherwise, the top keyring must not be revoked, expired, or - * negatively instantiated if we are to search it */ - key_ref = ERR_PTR(-EAGAIN); - if (kflags & ((1 << KEY_FLAG_REVOKED) | (1 << KEY_FLAG_NEGATIVE)) || - (keyring->expiry && now.tv_sec >= keyring->expiry)) - goto error_2; + /* key must have search permissions */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) { + ctx->result = ERR_PTR(-EACCES); + kleave(" = %d [!perm]", ctx->skipped_ret); + goto skipped; + } - /* start processing a new keyring */ -descend: - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) - goto not_this_keyring; + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + /* we set a different error code if we pass a negative key */ + if (kflags & (1 << KEY_FLAG_NEGATIVE)) { + smp_rmb(); + ctx->result = ERR_PTR(key->type_data.reject_error); + kleave(" = %d [neg]", ctx->skipped_ret); + goto skipped; + } + } - keylist = rcu_dereference(keyring->payload.subscriptions); - if (!keylist) - goto not_this_keyring; + /* Found */ + ctx->result = make_key_ref(key, ctx->possessed); + kleave(" = 1 [found]"); + return 1; - /* iterate through the keys in this keyring first */ - for (kix = 0; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; - kflags = key->flags; +skipped: + return ctx->skipped_ret; +} - /* ignore keys not of this type */ - if (key->type != type) - continue; +/* + * Search inside a keyring for a key. We can search by walking to it + * directly based on its index-key or we can iterate over the entire + * tree looking for it, based on the match function. + */ +static int search_keyring(struct key *keyring, struct keyring_search_context *ctx) +{ + if ((ctx->flags & KEYRING_SEARCH_LOOKUP_TYPE) == + KEYRING_SEARCH_LOOKUP_DIRECT) { + const void *object; + + object = assoc_array_find(&keyring->keys, + &keyring_assoc_array_ops, + &ctx->index_key); + return object ? ctx->iterator(object, ctx) : 0; + } + return assoc_array_iterate(&keyring->keys, ctx->iterator, ctx); +} - /* skip revoked keys and expired keys */ - if (kflags & (1 << KEY_FLAG_REVOKED)) - continue; +/* + * Search a tree of keyrings that point to other keyrings up to the maximum + * depth. + */ +static bool search_nested_keyrings(struct key *keyring, + struct keyring_search_context *ctx) +{ + struct { + struct key *keyring; + struct assoc_array_node *node; + int slot; + } stack[KEYRING_SEARCH_MAX_DEPTH]; - if (key->expiry && now.tv_sec >= key->expiry) - continue; + struct assoc_array_shortcut *shortcut; + struct assoc_array_node *node; + struct assoc_array_ptr *ptr; + struct key *key; + int sp = 0, slot; - /* keys that don't match */ - if (!match(key, description)) - continue; + kenter("{%d},{%s,%s}", + keyring->serial, + ctx->index_key.type->name, + ctx->index_key.description); - /* key must have search permissions */ - if (key_task_permission(make_key_ref(key, possessed), - cred, KEY_SEARCH) < 0) - continue; + if (ctx->index_key.description) + ctx->index_key.desc_len = strlen(ctx->index_key.description); - /* we set a different error code if we pass a negative key */ - if (kflags & (1 << KEY_FLAG_NEGATIVE)) { - err = -ENOKEY; - continue; + /* Check to see if this top-level keyring is what we are looking for + * and whether it is valid or not. + */ + if (ctx->flags & KEYRING_SEARCH_LOOKUP_ITERATE || + keyring_compare_object(keyring, &ctx->index_key)) { + ctx->skipped_ret = 2; + ctx->flags |= KEYRING_SEARCH_DO_STATE_CHECK; + switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) { + case 1: + goto found; + case 2: + return false; + default: + break; } + } + + ctx->skipped_ret = 0; + if (ctx->flags & KEYRING_SEARCH_NO_STATE_CHECK) + ctx->flags &= ~KEYRING_SEARCH_DO_STATE_CHECK; + + /* Start processing a new keyring */ +descend_to_keyring: + kdebug("descend to %d", keyring->serial); + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto not_this_keyring; + /* Search through the keys in this keyring before its searching its + * subtrees. + */ + if (search_keyring(keyring, ctx)) goto found; - } - /* search through the keyrings nested in this one */ - kix = 0; -ascend: - for (; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; - if (key->type != &key_type_keyring) - continue; + /* Then manually iterate through the keyrings nested in this one. + * + * Start from the root node of the index tree. Because of the way the + * hash function has been set up, keyrings cluster on the leftmost + * branch of the root node (root slot 0) or in the root node itself. + * Non-keyrings avoid the leftmost branch of the root entirely (root + * slots 1-15). + */ + ptr = ACCESS_ONCE(keyring->keys.root); + if (!ptr) + goto not_this_keyring; - /* recursively search nested keyrings - * - only search keyrings for which we have search permission + if (assoc_array_ptr_is_shortcut(ptr)) { + /* If the root is a shortcut, either the keyring only contains + * keyring pointers (everything clusters behind root slot 0) or + * doesn't contain any keyring pointers. */ - if (sp >= KEYRING_SEARCH_MAX_DEPTH) + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + if ((shortcut->index_key[0] & ASSOC_ARRAY_FAN_MASK) != 0) + goto not_this_keyring; + + ptr = ACCESS_ONCE(shortcut->next_node); + node = assoc_array_ptr_to_node(ptr); + goto begin_node; + } + + node = assoc_array_ptr_to_node(ptr); + smp_read_barrier_depends(); + + ptr = node->slots[0]; + if (!assoc_array_ptr_is_meta(ptr)) + goto begin_node; + +descend_to_node: + /* Descend to a more distal node in this keyring's content tree and go + * through that. + */ + kdebug("descend"); + if (assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + ptr = ACCESS_ONCE(shortcut->next_node); + BUG_ON(!assoc_array_ptr_is_node(ptr)); + } + node = assoc_array_ptr_to_node(ptr); + +begin_node: + kdebug("begin_node"); + smp_read_barrier_depends(); + slot = 0; +ascend_to_node: + /* Go through the slots in a node */ + for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) { + ptr = ACCESS_ONCE(node->slots[slot]); + + if (assoc_array_ptr_is_meta(ptr) && node->back_pointer) + goto descend_to_node; + + if (!keyring_ptr_is_keyring(ptr)) continue; - if (key_task_permission(make_key_ref(key, possessed), - cred, KEY_SEARCH) < 0) + key = keyring_ptr_to_key(ptr); + + if (sp >= KEYRING_SEARCH_MAX_DEPTH) { + if (ctx->flags & KEYRING_SEARCH_DETECT_TOO_DEEP) { + ctx->result = ERR_PTR(-ELOOP); + return false; + } + goto not_this_keyring; + } + + /* Search a nested keyring */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) continue; /* stack the current position */ - stack[sp].keylist = keylist; - stack[sp].kix = kix; + stack[sp].keyring = keyring; + stack[sp].node = node; + stack[sp].slot = slot; sp++; /* begin again with the new keyring */ keyring = key; - goto descend; + goto descend_to_keyring; + } + + /* We've dealt with all the slots in the current node, so now we need + * to ascend to the parent and continue processing there. + */ + ptr = ACCESS_ONCE(node->back_pointer); + slot = node->parent_slot; + + if (ptr && assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + ptr = ACCESS_ONCE(shortcut->back_pointer); + slot = shortcut->parent_slot; + } + if (!ptr) + goto not_this_keyring; + node = assoc_array_ptr_to_node(ptr); + smp_read_barrier_depends(); + slot++; + + /* If we've ascended to the root (zero backpointer), we must have just + * finished processing the leftmost branch rather than the root slots - + * so there can't be any more keyrings for us to find. + */ + if (node->back_pointer) { + kdebug("ascend %d", slot); + goto ascend_to_node; } - /* the keyring we're looking at was disqualified or didn't contain a - * matching key */ + /* The keyring we're looking at was disqualified or didn't contain a + * matching key. + */ not_this_keyring: - if (sp > 0) { - /* resume the processing of a keyring higher up in the tree */ - sp--; - keylist = stack[sp].keylist; - kix = stack[sp].kix + 1; - goto ascend; + kdebug("not_this_keyring %d", sp); + if (sp <= 0) { + kleave(" = false"); + return false; } - key_ref = ERR_PTR(err); - goto error_2; + /* Resume the processing of a keyring higher up in the tree */ + sp--; + keyring = stack[sp].keyring; + node = stack[sp].node; + slot = stack[sp].slot + 1; + kdebug("ascend to %d [%d]", keyring->serial, slot); + goto ascend_to_node; - /* we found a viable match */ + /* We found a viable match */ found: - atomic_inc(&key->usage); + key = key_ref_to_ptr(ctx->result); key_check(key); - key_ref = make_key_ref(key, possessed); -error_2: + if (!(ctx->flags & KEYRING_SEARCH_NO_UPDATE_TIME)) { + key->last_used_at = ctx->now.tv_sec; + keyring->last_used_at = ctx->now.tv_sec; + while (sp > 0) + stack[--sp].keyring->last_used_at = ctx->now.tv_sec; + } + kleave(" = true"); + return true; +} + +/** + * keyring_search_aux - Search a keyring tree for a key matching some criteria + * @keyring_ref: A pointer to the keyring with possession indicator. + * @ctx: The keyring search context. + * + * Search the supplied keyring tree for a key that matches the criteria given. + * The root keyring and any linked keyrings must grant Search permission to the + * caller to be searchable and keys can only be found if they too grant Search + * to the caller. The possession flag on the root keyring pointer controls use + * of the possessor bits in permissions checking of the entire tree. In + * addition, the LSM gets to forbid keyring searches and key matches. + * + * The search is performed as a breadth-then-depth search up to the prescribed + * limit (KEYRING_SEARCH_MAX_DEPTH). + * + * Keys are matched to the type provided and are then filtered by the match + * function, which is given the description to use in any way it sees fit. The + * match function may use any attributes of a key that it wishes to to + * determine the match. Normally the match function from the key type would be + * used. + * + * RCU can be used to prevent the keyring key lists from disappearing without + * the need to take lots of locks. + * + * Returns a pointer to the found key and increments the key usage count if + * successful; -EAGAIN if no matching keys were found, or if expired or revoked + * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the + * specified keyring wasn't a keyring. + * + * In the case of a successful return, the possession attribute from + * @keyring_ref is propagated to the returned key reference. + */ +key_ref_t keyring_search_aux(key_ref_t keyring_ref, + struct keyring_search_context *ctx) +{ + struct key *keyring; + long err; + + ctx->iterator = keyring_search_iterator; + ctx->possessed = is_key_possessed(keyring_ref); + ctx->result = ERR_PTR(-EAGAIN); + + keyring = key_ref_to_ptr(keyring_ref); + key_check(keyring); + + if (keyring->type != &key_type_keyring) + return ERR_PTR(-ENOTDIR); + + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) { + err = key_task_permission(keyring_ref, ctx->cred, KEY_NEED_SEARCH); + if (err < 0) + return ERR_PTR(err); + } + + rcu_read_lock(); + ctx->now = current_kernel_time(); + if (search_nested_keyrings(keyring, ctx)) + __key_get(key_ref_to_ptr(ctx->result)); rcu_read_unlock(); -error: - return key_ref; + return ctx->result; } /** @@ -468,73 +863,73 @@ error: * @description: The name of the keyring we want to find. * * As keyring_search_aux() above, but using the current task's credentials and - * type's default matching function. + * type's default matching function and preferred search method. */ key_ref_t keyring_search(key_ref_t keyring, struct key_type *type, const char *description) { - if (!type->match) + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.description = description, + .cred = current_cred(), + .match = type->match, + .match_data = description, + .flags = (type->def_lookup_type | + KEYRING_SEARCH_DO_STATE_CHECK), + }; + + if (!ctx.match) return ERR_PTR(-ENOKEY); - return keyring_search_aux(keyring, current->cred, - type, description, type->match); + return keyring_search_aux(keyring, &ctx); } EXPORT_SYMBOL(keyring_search); /* - * Search the given keyring only (no recursion). + * Search the given keyring for a key that might be updated. * * The caller must guarantee that the keyring is a keyring and that the - * permission is granted to search the keyring as no check is made here. - * - * RCU is used to make it unnecessary to lock the keyring key list here. + * permission is granted to modify the keyring as no check is made here. The + * caller must also hold a lock on the keyring semaphore. * * Returns a pointer to the found key with usage count incremented if - * successful and returns -ENOKEY if not found. Revoked keys and keys not - * providing the requested permission are skipped over. + * successful and returns NULL if not found. Revoked and invalidated keys are + * skipped over. * * If successful, the possession indicator is propagated from the keyring ref * to the returned key reference. */ -key_ref_t __keyring_search_one(key_ref_t keyring_ref, - const struct key_type *ktype, - const char *description, - key_perm_t perm) +key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key) { - struct keyring_list *klist; - unsigned long possessed; struct key *keyring, *key; - int loop; + const void *object; keyring = key_ref_to_ptr(keyring_ref); - possessed = is_key_possessed(keyring_ref); - rcu_read_lock(); + kenter("{%d},{%s,%s}", + keyring->serial, index_key->type->name, index_key->description); - klist = rcu_dereference(keyring->payload.subscriptions); - if (klist) { - for (loop = 0; loop < klist->nkeys; loop++) { - key = klist->keys[loop]; - - if (key->type == ktype && - (!key->type->match || - key->type->match(key, description)) && - key_permission(make_key_ref(key, possessed), - perm) == 0 && - !test_bit(KEY_FLAG_REVOKED, &key->flags) - ) - goto found; - } - } + object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops, + index_key); - rcu_read_unlock(); - return ERR_PTR(-ENOKEY); + if (object) + goto found; + + kleave(" = NULL"); + return NULL; found: - atomic_inc(&key->usage); - rcu_read_unlock(); - return make_key_ref(key, possessed); + key = keyring_ptr_to_key(object); + if (key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + kleave(" = NULL [x]"); + return NULL; + } + __key_get(key); + kleave(" = {%d}", key->serial); + return make_key_ref(key, is_key_possessed(keyring_ref)); } /* @@ -567,7 +962,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) &keyring_name_hash[bucket], type_data.link ) { - if (keyring->user->user_ns != current_user_ns()) + if (!kuid_has_mapping(current_user_ns(), keyring->user->uid)) continue; if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) @@ -578,7 +973,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) if (!skip_perm_check && key_permission(make_key_ref(keyring, 0), - KEY_SEARCH) < 0) + KEY_NEED_SEARCH) < 0) continue; /* we've got a match but we might end up racing with @@ -586,6 +981,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) * (ie. it has a zero usage count) */ if (!atomic_inc_not_zero(&keyring->usage)) continue; + keyring->last_used_at = current_kernel_time().tv_sec; goto out; } } @@ -596,6 +992,23 @@ out: return keyring; } +static int keyring_detect_cycle_iterator(const void *object, + void *iterator_data) +{ + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + + kenter("{%d}", key->serial); + + /* We might get a keyring with matching index-key that is nonetheless a + * different keyring. */ + if (key != ctx->match_data) + return 0; + + ctx->result = ERR_PTR(-EDEADLK); + return 1; +} + /* * See if a cycle will will be created by inserting acyclic tree B in acyclic * tree A at the topmost level (ie: as a direct child of A). @@ -605,112 +1018,39 @@ out: */ static int keyring_detect_cycle(struct key *A, struct key *B) { - struct { - struct keyring_list *keylist; - int kix; - } stack[KEYRING_SEARCH_MAX_DEPTH]; - - struct keyring_list *keylist; - struct key *subtree, *key; - int sp, kix, ret; + struct keyring_search_context ctx = { + .index_key = A->index_key, + .match_data = A, + .iterator = keyring_detect_cycle_iterator, + .flags = (KEYRING_SEARCH_LOOKUP_DIRECT | + KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_NO_UPDATE_TIME | + KEYRING_SEARCH_NO_CHECK_PERM | + KEYRING_SEARCH_DETECT_TOO_DEEP), + }; rcu_read_lock(); - - ret = -EDEADLK; - if (A == B) - goto cycle_detected; - - subtree = B; - sp = 0; - - /* start processing a new keyring */ -descend: - if (test_bit(KEY_FLAG_REVOKED, &subtree->flags)) - goto not_this_keyring; - - keylist = rcu_dereference(subtree->payload.subscriptions); - if (!keylist) - goto not_this_keyring; - kix = 0; - -ascend: - /* iterate through the remaining keys in this keyring */ - for (; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; - - if (key == A) - goto cycle_detected; - - /* recursively check nested keyrings */ - if (key->type == &key_type_keyring) { - if (sp >= KEYRING_SEARCH_MAX_DEPTH) - goto too_deep; - - /* stack the current position */ - stack[sp].keylist = keylist; - stack[sp].kix = kix; - sp++; - - /* begin again with the new keyring */ - subtree = key; - goto descend; - } - } - - /* the keyring we're looking at was disqualified or didn't contain a - * matching key */ -not_this_keyring: - if (sp > 0) { - /* resume the checking of a keyring higher up in the tree */ - sp--; - keylist = stack[sp].keylist; - kix = stack[sp].kix + 1; - goto ascend; - } - - ret = 0; /* no cycles detected */ - -error: + search_nested_keyrings(B, &ctx); rcu_read_unlock(); - return ret; - -too_deep: - ret = -ELOOP; - goto error; - -cycle_detected: - ret = -EDEADLK; - goto error; -} - -/* - * Dispose of a keyring list after the RCU grace period, freeing the unlinked - * key - */ -static void keyring_unlink_rcu_disposal(struct rcu_head *rcu) -{ - struct keyring_list *klist = - container_of(rcu, struct keyring_list, rcu); - - if (klist->delkey != USHRT_MAX) - key_put(klist->keys[klist->delkey]); - kfree(klist); + return PTR_ERR(ctx.result) == -EAGAIN ? 0 : PTR_ERR(ctx.result); } /* * Preallocate memory so that a key can be linked into to a keyring. */ -int __key_link_begin(struct key *keyring, const struct key_type *type, - const char *description, unsigned long *_prealloc) +int __key_link_begin(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit) __acquires(&keyring->sem) + __acquires(&keyring_serialise_link_sem) { - struct keyring_list *klist, *nklist; - unsigned long prealloc; - unsigned max; - size_t size; - int loop, ret; + struct assoc_array_edit *edit; + int ret; - kenter("%d,%s,%s,", key_serial(keyring), type->name, description); + kenter("%d,%s,%s,", + keyring->serial, index_key->type->name, index_key->description); + + BUG_ON(index_key->desc_len == 0); if (keyring->type != &key_type_keyring) return -ENOTDIR; @@ -723,93 +1063,39 @@ int __key_link_begin(struct key *keyring, const struct key_type *type, /* serialise link/link calls to prevent parallel calls causing a cycle * when linking two keyring in opposite orders */ - if (type == &key_type_keyring) + if (index_key->type == &key_type_keyring) down_write(&keyring_serialise_link_sem); - klist = rcu_dereference_locked_keyring(keyring); - - /* see if there's a matching key we can displace */ - if (klist && klist->nkeys > 0) { - for (loop = klist->nkeys - 1; loop >= 0; loop--) { - if (klist->keys[loop]->type == type && - strcmp(klist->keys[loop]->description, - description) == 0 - ) { - /* found a match - we'll replace this one with - * the new key */ - size = sizeof(struct key *) * klist->maxkeys; - size += sizeof(*klist); - BUG_ON(size > PAGE_SIZE); - - ret = -ENOMEM; - nklist = kmemdup(klist, size, GFP_KERNEL); - if (!nklist) - goto error_sem; - - /* note replacement slot */ - klist->delkey = nklist->delkey = loop; - prealloc = (unsigned long)nklist; - goto done; - } - } - } - - /* check that we aren't going to overrun the user's quota */ - ret = key_payload_reserve(keyring, - keyring->datalen + KEYQUOTA_LINK_BYTES); - if (ret < 0) + /* Create an edit script that will insert/replace the key in the + * keyring tree. + */ + edit = assoc_array_insert(&keyring->keys, + &keyring_assoc_array_ops, + index_key, + NULL); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); goto error_sem; + } - if (klist && klist->nkeys < klist->maxkeys) { - /* there's sufficient slack space to append directly */ - nklist = NULL; - prealloc = KEY_LINK_FIXQUOTA; - } else { - /* grow the key list */ - max = 4; - if (klist) - max += klist->maxkeys; - - ret = -ENFILE; - if (max > USHRT_MAX - 1) - goto error_quota; - size = sizeof(*klist) + sizeof(struct key *) * max; - if (size > PAGE_SIZE) - goto error_quota; - - ret = -ENOMEM; - nklist = kmalloc(size, GFP_KERNEL); - if (!nklist) - goto error_quota; - - nklist->maxkeys = max; - if (klist) { - memcpy(nklist->keys, klist->keys, - sizeof(struct key *) * klist->nkeys); - nklist->delkey = klist->nkeys; - nklist->nkeys = klist->nkeys + 1; - klist->delkey = USHRT_MAX; - } else { - nklist->nkeys = 1; - nklist->delkey = 0; - } - - /* add the key into the new space */ - nklist->keys[nklist->delkey] = NULL; + /* If we're not replacing a link in-place then we're going to need some + * extra quota. + */ + if (!edit->dead_leaf) { + ret = key_payload_reserve(keyring, + keyring->datalen + KEYQUOTA_LINK_BYTES); + if (ret < 0) + goto error_cancel; } - prealloc = (unsigned long)nklist | KEY_LINK_FIXQUOTA; -done: - *_prealloc = prealloc; + *_edit = edit; kleave(" = 0"); return 0; -error_quota: - /* undo the quota changes */ - key_payload_reserve(keyring, - keyring->datalen - KEYQUOTA_LINK_BYTES); +error_cancel: + assoc_array_cancel_edit(edit); error_sem: - if (type == &key_type_keyring) + if (index_key->type == &key_type_keyring) up_write(&keyring_serialise_link_sem); error_krsem: up_write(&keyring->sem); @@ -840,44 +1126,12 @@ int __key_link_check_live_key(struct key *keyring, struct key *key) * holds at most one link to any given key of a particular type+description * combination. */ -void __key_link(struct key *keyring, struct key *key, - unsigned long *_prealloc) +void __key_link(struct key *key, struct assoc_array_edit **_edit) { - struct keyring_list *klist, *nklist; - - nklist = (struct keyring_list *)(*_prealloc & ~KEY_LINK_FIXQUOTA); - *_prealloc = 0; - - kenter("%d,%d,%p", keyring->serial, key->serial, nklist); - - klist = rcu_dereference_protected(keyring->payload.subscriptions, - rwsem_is_locked(&keyring->sem)); - - atomic_inc(&key->usage); - - /* there's a matching key we can displace or an empty slot in a newly - * allocated list we can fill */ - if (nklist) { - kdebug("replace %hu/%hu/%hu", - nklist->delkey, nklist->nkeys, nklist->maxkeys); - - nklist->keys[nklist->delkey] = key; - - rcu_assign_pointer(keyring->payload.subscriptions, nklist); - - /* dispose of the old keyring list and, if there was one, the - * displaced key */ - if (klist) { - kdebug("dispose %hu/%hu/%hu", - klist->delkey, klist->nkeys, klist->maxkeys); - call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); - } - } else { - /* there's sufficient slack space to append directly */ - klist->keys[klist->nkeys] = key; - smp_wmb(); - klist->nkeys++; - } + __key_get(key); + assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key)); + assoc_array_apply_edit(*_edit); + *_edit = NULL; } /* @@ -885,23 +1139,22 @@ void __key_link(struct key *keyring, struct key *key, * * Must be called with __key_link_begin() having being called. */ -void __key_link_end(struct key *keyring, struct key_type *type, - unsigned long prealloc) +void __key_link_end(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit) __releases(&keyring->sem) + __releases(&keyring_serialise_link_sem) { - BUG_ON(type == NULL); - BUG_ON(type->name == NULL); - kenter("%d,%s,%lx", keyring->serial, type->name, prealloc); + BUG_ON(index_key->type == NULL); + kenter("%d,%s,", keyring->serial, index_key->type->name); - if (type == &key_type_keyring) + if (index_key->type == &key_type_keyring) up_write(&keyring_serialise_link_sem); - if (prealloc) { - if (prealloc & KEY_LINK_FIXQUOTA) - key_payload_reserve(keyring, - keyring->datalen - - KEYQUOTA_LINK_BYTES); - kfree((struct keyring_list *)(prealloc & ~KEY_LINK_FIXQUOTA)); + if (edit && !edit->dead_leaf) { + key_payload_reserve(keyring, + keyring->datalen - KEYQUOTA_LINK_BYTES); + assoc_array_cancel_edit(edit); } up_write(&keyring->sem); } @@ -928,20 +1181,28 @@ void __key_link_end(struct key *keyring, struct key_type *type, */ int key_link(struct key *keyring, struct key *key) { - unsigned long prealloc; + struct assoc_array_edit *edit; int ret; + kenter("{%d,%d}", keyring->serial, atomic_read(&keyring->usage)); + key_check(keyring); key_check(key); - ret = __key_link_begin(keyring, key->type, key->description, &prealloc); + if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) && + !test_bit(KEY_FLAG_TRUSTED, &key->flags)) + return -EPERM; + + ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret == 0) { + kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage)); ret = __key_link_check_live_key(keyring, key); if (ret == 0) - __key_link(keyring, key, &prealloc); - __key_link_end(keyring, key->type, prealloc); + __key_link(key, &edit); + __key_link_end(keyring, &key->index_key, edit); } + kleave(" = %d {%d,%d}", ret, keyring->serial, atomic_read(&keyring->usage)); return ret; } EXPORT_SYMBOL(key_link); @@ -965,90 +1226,37 @@ EXPORT_SYMBOL(key_link); */ int key_unlink(struct key *keyring, struct key *key) { - struct keyring_list *klist, *nklist; - int loop, ret; + struct assoc_array_edit *edit; + int ret; key_check(keyring); key_check(key); - ret = -ENOTDIR; if (keyring->type != &key_type_keyring) - goto error; + return -ENOTDIR; down_write(&keyring->sem); - klist = rcu_dereference_locked_keyring(keyring); - if (klist) { - /* search the keyring for the key */ - for (loop = 0; loop < klist->nkeys; loop++) - if (klist->keys[loop] == key) - goto key_is_present; + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, + &key->index_key); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + goto error; } - - up_write(&keyring->sem); ret = -ENOENT; - goto error; - -key_is_present: - /* we need to copy the key list for RCU purposes */ - nklist = kmalloc(sizeof(*klist) + - sizeof(struct key *) * klist->maxkeys, - GFP_KERNEL); - if (!nklist) - goto nomem; - nklist->maxkeys = klist->maxkeys; - nklist->nkeys = klist->nkeys - 1; - - if (loop > 0) - memcpy(&nklist->keys[0], - &klist->keys[0], - loop * sizeof(struct key *)); - - if (loop < nklist->nkeys) - memcpy(&nklist->keys[loop], - &klist->keys[loop + 1], - (nklist->nkeys - loop) * sizeof(struct key *)); - - /* adjust the user's quota */ - key_payload_reserve(keyring, - keyring->datalen - KEYQUOTA_LINK_BYTES); - - rcu_assign_pointer(keyring->payload.subscriptions, nklist); - - up_write(&keyring->sem); - - /* schedule for later cleanup */ - klist->delkey = loop; - call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); + if (edit == NULL) + goto error; + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); ret = 0; error: - return ret; -nomem: - ret = -ENOMEM; up_write(&keyring->sem); - goto error; + return ret; } EXPORT_SYMBOL(key_unlink); -/* - * Dispose of a keyring list after the RCU grace period, releasing the keys it - * links to. - */ -static void keyring_clear_rcu_disposal(struct rcu_head *rcu) -{ - struct keyring_list *klist; - int loop; - - klist = container_of(rcu, struct keyring_list, rcu); - - for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); - - kfree(klist); -} - /** * keyring_clear - Clear a keyring * @keyring: The keyring to clear. @@ -1059,33 +1267,25 @@ static void keyring_clear_rcu_disposal(struct rcu_head *rcu) */ int keyring_clear(struct key *keyring) { - struct keyring_list *klist; + struct assoc_array_edit *edit; int ret; - ret = -ENOTDIR; - if (keyring->type == &key_type_keyring) { - /* detach the pointer block with the locks held */ - down_write(&keyring->sem); - - klist = rcu_dereference_locked_keyring(keyring); - if (klist) { - /* adjust the quota */ - key_payload_reserve(keyring, - sizeof(struct keyring_list)); - - rcu_assign_pointer(keyring->payload.subscriptions, - NULL); - } - - up_write(&keyring->sem); + if (keyring->type != &key_type_keyring) + return -ENOTDIR; - /* free the keys after the locks have been dropped */ - if (klist) - call_rcu(&klist->rcu, keyring_clear_rcu_disposal); + down_write(&keyring->sem); + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + } else { + if (edit) + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, 0); ret = 0; } + up_write(&keyring->sem); return ret; } EXPORT_SYMBOL(keyring_clear); @@ -1097,119 +1297,68 @@ EXPORT_SYMBOL(keyring_clear); */ static void keyring_revoke(struct key *keyring) { - struct keyring_list *klist; + struct assoc_array_edit *edit; - klist = rcu_dereference_locked_keyring(keyring); + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (!IS_ERR(edit)) { + if (edit) + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, 0); + } +} - /* adjust the quota */ - key_payload_reserve(keyring, 0); +static bool keyring_gc_select_iterator(void *object, void *iterator_data) +{ + struct key *key = keyring_ptr_to_key(object); + time_t *limit = iterator_data; - if (klist) { - rcu_assign_pointer(keyring->payload.subscriptions, NULL); - call_rcu(&klist->rcu, keyring_clear_rcu_disposal); - } + if (key_is_dead(key, *limit)) + return false; + key_get(key); + return true; } -/* - * Determine whether a key is dead. - */ -static bool key_is_dead(struct key *key, time_t limit) +static int keyring_gc_check_iterator(const void *object, void *iterator_data) { - return test_bit(KEY_FLAG_DEAD, &key->flags) || - (key->expiry > 0 && key->expiry <= limit); + const struct key *key = keyring_ptr_to_key(object); + time_t *limit = iterator_data; + + key_check(key); + return key_is_dead(key, *limit); } /* - * Collect garbage from the contents of a keyring, replacing the old list with - * a new one with the pointers all shuffled down. + * Garbage collect pointers from a keyring. * - * Dead keys are classed as oned that are flagged as being dead or are revoked, - * expired or negative keys that were revoked or expired before the specified - * limit. + * Not called with any locks held. The keyring's key struct will not be + * deallocated under us as only our caller may deallocate it. */ void keyring_gc(struct key *keyring, time_t limit) { - struct keyring_list *klist, *new; - struct key *key; - int loop, keep, max; - - kenter("{%x,%s}", key_serial(keyring), keyring->description); - - down_write(&keyring->sem); - - klist = rcu_dereference_locked_keyring(keyring); - if (!klist) - goto no_klist; - - /* work out how many subscriptions we're keeping */ - keep = 0; - for (loop = klist->nkeys - 1; loop >= 0; loop--) - if (!key_is_dead(klist->keys[loop], limit)) - keep++; - - if (keep == klist->nkeys) - goto just_return; - - /* allocate a new keyring payload */ - max = roundup(keep, 4); - new = kmalloc(sizeof(struct keyring_list) + max * sizeof(struct key *), - GFP_KERNEL); - if (!new) - goto nomem; - new->maxkeys = max; - new->nkeys = 0; - new->delkey = 0; - - /* install the live keys - * - must take care as expired keys may be updated back to life - */ - keep = 0; - for (loop = klist->nkeys - 1; loop >= 0; loop--) { - key = klist->keys[loop]; - if (!key_is_dead(key, limit)) { - if (keep >= max) - goto discard_new; - new->keys[keep++] = key_get(key); - } - } - new->nkeys = keep; - - /* adjust the quota */ - key_payload_reserve(keyring, - sizeof(struct keyring_list) + - KEYQUOTA_LINK_BYTES * keep); + int result; - if (keep == 0) { - rcu_assign_pointer(keyring->payload.subscriptions, NULL); - kfree(new); - } else { - rcu_assign_pointer(keyring->payload.subscriptions, new); - } + kenter("%x{%s}", keyring->serial, keyring->description ?: ""); - up_write(&keyring->sem); + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto dont_gc; - call_rcu(&klist->rcu, keyring_clear_rcu_disposal); - kleave(" [yes]"); - return; - -discard_new: - new->nkeys = keep; - keyring_clear_rcu_disposal(&new->rcu); - up_write(&keyring->sem); - kleave(" [discard]"); - return; - -just_return: - up_write(&keyring->sem); - kleave(" [no dead]"); - return; + /* scan the keyring looking for dead keys */ + rcu_read_lock(); + result = assoc_array_iterate(&keyring->keys, + keyring_gc_check_iterator, &limit); + rcu_read_unlock(); + if (result == true) + goto do_gc; -no_klist: - up_write(&keyring->sem); - kleave(" [no_klist]"); +dont_gc: + kleave(" [no gc]"); return; -nomem: +do_gc: + down_write(&keyring->sem); + assoc_array_gc(&keyring->keys, &keyring_assoc_array_ops, + keyring_gc_select_iterator, &limit); up_write(&keyring->sem); - kleave(" [oom]"); + kleave(" [gc]"); } diff --git a/security/keys/permission.c b/security/keys/permission.c index c35b5229e3c..732cc0beffd 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -28,7 +28,7 @@ * permissions bits or the LSM check. */ int key_task_permission(const key_ref_t key_ref, const struct cred *cred, - key_perm_t perm) + unsigned perm) { struct key *key; key_perm_t kperm; @@ -36,19 +36,16 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred, key = key_ref_to_ptr(key_ref); - if (key->user->user_ns != cred->user->user_ns) - goto use_other_perms; - /* use the second 8-bits of permissions for keys the caller owns */ - if (key->uid == cred->fsuid) { + if (uid_eq(key->uid, cred->fsuid)) { kperm = key->perm >> 16; goto use_these_perms; } /* use the third 8-bits of permissions for keys the caller has a group * membership in common with */ - if (key->gid != -1 && key->perm & KEY_GRP_ALL) { - if (key->gid == cred->fsgid) { + if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) { + if (gid_eq(key->gid, cred->fsgid)) { kperm = key->perm >> 8; goto use_these_perms; } @@ -60,8 +57,6 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred, } } -use_other_perms: - /* otherwise use the least-significant 8-bits */ kperm = key->perm; @@ -73,7 +68,7 @@ use_these_perms: if (is_key_possessed(key_ref)) kperm |= key->perm >> 24; - kperm = kperm & perm & KEY_ALL; + kperm = kperm & perm & KEY_NEED_ALL; if (kperm != perm) return -EACCES; @@ -87,32 +82,29 @@ EXPORT_SYMBOL(key_task_permission); * key_validate - Validate a key. * @key: The key to be validated. * - * Check that a key is valid, returning 0 if the key is okay, -EKEYREVOKED if - * the key's type has been removed or if the key has been revoked or - * -EKEYEXPIRED if the key has expired. + * Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the + * key is invalidated, -EKEYREVOKED if the key's type has been removed or if + * the key has been revoked or -EKEYEXPIRED if the key has expired. */ -int key_validate(struct key *key) +int key_validate(const struct key *key) { - struct timespec now; - int ret = 0; - - if (key) { - /* check it's still accessible */ - ret = -EKEYREVOKED; - if (test_bit(KEY_FLAG_REVOKED, &key->flags) || - test_bit(KEY_FLAG_DEAD, &key->flags)) - goto error; - - /* check it hasn't expired */ - ret = 0; - if (key->expiry) { - now = current_kernel_time(); - if (now.tv_sec >= key->expiry) - ret = -EKEYEXPIRED; - } + unsigned long flags = key->flags; + + if (flags & (1 << KEY_FLAG_INVALIDATED)) + return -ENOKEY; + + /* check it's still accessible */ + if (flags & ((1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD))) + return -EKEYREVOKED; + + /* check it hasn't expired */ + if (key->expiry) { + struct timespec now = current_kernel_time(); + if (now.tv_sec >= key->expiry) + return -EKEYEXPIRED; } -error: - return ret; + return 0; } EXPORT_SYMBOL(key_validate); diff --git a/security/keys/persistent.c b/security/keys/persistent.c new file mode 100644 index 00000000000..c9fae5ea89f --- /dev/null +++ b/security/keys/persistent.c @@ -0,0 +1,167 @@ +/* General persistent per-UID keyrings register + * + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/user_namespace.h> +#include "internal.h" + +unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */ + +/* + * Create the persistent keyring register for the current user namespace. + * + * Called with the namespace's sem locked for writing. + */ +static int key_create_persistent_register(struct user_namespace *ns) +{ + struct key *reg = keyring_alloc(".persistent_register", + KUIDT_INIT(0), KGIDT_INIT(0), + current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(reg)) + return PTR_ERR(reg); + + ns->persistent_keyring_register = reg; + return 0; +} + +/* + * Create the persistent keyring for the specified user. + * + * Called with the namespace's sem locked for writing. + */ +static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid, + struct keyring_index_key *index_key) +{ + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + + if (!ns->persistent_keyring_register) { + long err = key_create_persistent_register(ns); + if (err < 0) + return ERR_PTR(err); + } else { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + persistent_ref = find_key_to_update(reg_ref, index_key); + if (persistent_ref) + return persistent_ref; + } + + persistent = keyring_alloc(index_key->description, + uid, INVALID_GID, current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, + ns->persistent_keyring_register); + if (IS_ERR(persistent)) + return ERR_CAST(persistent); + + return make_key_ref(persistent, true); +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +static long key_get_persistent(struct user_namespace *ns, kuid_t uid, + key_ref_t dest_ref) +{ + struct keyring_index_key index_key; + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + char buf[32]; + long ret; + + /* Look in the register if it exists */ + index_key.type = &key_type_keyring; + index_key.description = buf; + index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid)); + + if (ns->persistent_keyring_register) { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + down_read(&ns->persistent_keyring_register_sem); + persistent_ref = find_key_to_update(reg_ref, &index_key); + up_read(&ns->persistent_keyring_register_sem); + + if (persistent_ref) + goto found; + } + + /* It wasn't in the register, so we'll need to create it. We might + * also need to create the register. + */ + down_write(&ns->persistent_keyring_register_sem); + persistent_ref = key_create_persistent(ns, uid, &index_key); + up_write(&ns->persistent_keyring_register_sem); + if (!IS_ERR(persistent_ref)) + goto found; + + return PTR_ERR(persistent_ref); + +found: + ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK); + if (ret == 0) { + persistent = key_ref_to_ptr(persistent_ref); + ret = key_link(key_ref_to_ptr(dest_ref), persistent); + if (ret == 0) { + key_set_timeout(persistent, persistent_keyring_expiry); + ret = persistent->serial; + } + } + + key_ref_put(persistent_ref); + return ret; +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +long keyctl_get_persistent(uid_t _uid, key_serial_t destid) +{ + struct user_namespace *ns = current_user_ns(); + key_ref_t dest_ref; + kuid_t uid; + long ret; + + /* -1 indicates the current user */ + if (_uid == (uid_t)-1) { + uid = current_uid(); + } else { + uid = make_kuid(ns, _uid); + if (!uid_valid(uid)) + return -EINVAL; + + /* You can only see your own persistent cache if you're not + * sufficiently privileged. + */ + if (!uid_eq(uid, current_uid()) && + !uid_eq(uid, current_euid()) && + !ns_capable(ns, CAP_SETUID)) + return -EPERM; + } + + /* There must be a destination keyring */ + dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(dest_ref)) + return PTR_ERR(dest_ref); + if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) { + ret = -ENOTDIR; + goto out_put_dest; + } + + ret = key_get_persistent(ns, uid, dest_ref); + +out_put_dest: + key_ref_put(dest_ref); + return ret; +} diff --git a/security/keys/proc.c b/security/keys/proc.c index 525cf8a29cd..d3f6f2fd21d 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -88,14 +88,14 @@ __initcall(key_proc_init); */ #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS -static struct rb_node *key_serial_next(struct rb_node *n) +static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) { - struct user_namespace *user_ns = current_user_ns(); + struct user_namespace *user_ns = seq_user_ns(p); n = rb_next(n); while (n) { struct key *key = rb_entry(n, struct key, serial_node); - if (key->user->user_ns == user_ns) + if (kuid_has_mapping(user_ns, key->user->uid)) break; n = rb_next(n); } @@ -107,9 +107,9 @@ static int proc_keys_open(struct inode *inode, struct file *file) return seq_open(file, &proc_keys_ops); } -static struct key *find_ge_key(key_serial_t id) +static struct key *find_ge_key(struct seq_file *p, key_serial_t id) { - struct user_namespace *user_ns = current_user_ns(); + struct user_namespace *user_ns = seq_user_ns(p); struct rb_node *n = key_serial_tree.rb_node; struct key *minkey = NULL; @@ -132,7 +132,7 @@ static struct key *find_ge_key(key_serial_t id) return NULL; for (;;) { - if (minkey->user->user_ns == user_ns) + if (kuid_has_mapping(user_ns, minkey->user->uid)) return minkey; n = rb_next(&minkey->serial_node); if (!n) @@ -151,7 +151,7 @@ static void *proc_keys_start(struct seq_file *p, loff_t *_pos) if (*_pos > INT_MAX) return NULL; - key = find_ge_key(pos); + key = find_ge_key(p, pos); if (!key) return NULL; *_pos = key->serial; @@ -168,7 +168,7 @@ static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) { struct rb_node *n; - n = key_serial_next(v); + n = key_serial_next(p, v); if (n) *_pos = key_node_serial(n); return n; @@ -182,7 +182,6 @@ static void proc_keys_stop(struct seq_file *p, void *v) static int proc_keys_show(struct seq_file *m, void *v) { - const struct cred *cred = current_cred(); struct rb_node *_p = v; struct key *key = rb_entry(_p, struct key, serial_node); struct timespec now; @@ -191,15 +190,23 @@ static int proc_keys_show(struct seq_file *m, void *v) char xbuf[12]; int rc; + struct keyring_search_context ctx = { + .index_key.type = key->type, + .index_key.description = key->description, + .cred = current_cred(), + .match = lookup_user_key_possessed, + .match_data = key, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_LOOKUP_DIRECT), + }; + key_ref = make_key_ref(key, 0); /* determine if the key is possessed by this process (a test we can * skip if the key does not indicate the possessor can view it */ if (key->perm & KEY_POS_VIEW) { - skey_ref = search_my_process_keyrings(key->type, key, - lookup_user_key_possessed, - cred); + skey_ref = search_my_process_keyrings(&ctx); if (!IS_ERR(skey_ref)) { key_ref_put(skey_ref); key_ref = make_key_ref(key, 1); @@ -211,7 +218,7 @@ static int proc_keys_show(struct seq_file *m, void *v) * - the caller holds a spinlock, and thus the RCU read lock, making our * access to __current_cred() safe */ - rc = key_task_permission(key_ref, cred, KEY_VIEW); + rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); if (rc < 0) return 0; @@ -242,7 +249,7 @@ static int proc_keys_show(struct seq_file *m, void *v) #define showflag(KEY, LETTER, FLAG) \ (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') - seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", + seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", key->serial, showflag(key, 'I', KEY_FLAG_INSTANTIATED), showflag(key, 'R', KEY_FLAG_REVOKED), @@ -250,11 +257,12 @@ static int proc_keys_show(struct seq_file *m, void *v) showflag(key, 'Q', KEY_FLAG_IN_QUOTA), showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), showflag(key, 'N', KEY_FLAG_NEGATIVE), + showflag(key, 'i', KEY_FLAG_INVALIDATED), atomic_read(&key->usage), xbuf, key->perm, - key->uid, - key->gid, + from_kuid_munged(seq_user_ns(m), key->uid), + from_kgid_munged(seq_user_ns(m), key->gid), key->type->name); #undef showflag @@ -269,26 +277,26 @@ static int proc_keys_show(struct seq_file *m, void *v) #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */ -static struct rb_node *__key_user_next(struct rb_node *n) +static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) { while (n) { struct key_user *user = rb_entry(n, struct key_user, node); - if (user->user_ns == current_user_ns()) + if (kuid_has_mapping(user_ns, user->uid)) break; n = rb_next(n); } return n; } -static struct rb_node *key_user_next(struct rb_node *n) +static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) { - return __key_user_next(rb_next(n)); + return __key_user_next(user_ns, rb_next(n)); } -static struct rb_node *key_user_first(struct rb_root *r) +static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) { struct rb_node *n = rb_first(r); - return __key_user_next(n); + return __key_user_next(user_ns, n); } /* @@ -308,10 +316,10 @@ static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) spin_lock(&key_user_lock); - _p = key_user_first(&key_user_tree); + _p = key_user_first(seq_user_ns(p), &key_user_tree); while (pos > 0 && _p) { pos--; - _p = key_user_next(_p); + _p = key_user_next(seq_user_ns(p), _p); } return _p; @@ -320,7 +328,7 @@ static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) { (*_pos)++; - return key_user_next((struct rb_node *)v); + return key_user_next(seq_user_ns(p), (struct rb_node *)v); } static void proc_key_users_stop(struct seq_file *p, void *v) @@ -333,13 +341,13 @@ static int proc_key_users_show(struct seq_file *m, void *v) { struct rb_node *_p = v; struct key_user *user = rb_entry(_p, struct key_user, node); - unsigned maxkeys = (user->uid == 0) ? + unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (user->uid == 0) ? + unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", - user->uid, + from_kuid_munged(seq_user_ns(m), user->uid), atomic_read(&user->usage), atomic_read(&user->nkeys), atomic_read(&user->nikeys), diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 930634e4514..0cf8a130a26 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -34,8 +34,7 @@ struct key_user root_key_user = { .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), .nkeys = ATOMIC_INIT(2), .nikeys = ATOMIC_INIT(2), - .uid = 0, - .user_ns = &init_user_ns, + .uid = GLOBAL_ROOT_UID, }; /* @@ -46,15 +45,19 @@ int install_user_keyrings(void) struct user_struct *user; const struct cred *cred; struct key *uid_keyring, *session_keyring; + key_perm_t user_keyring_perm; char buf[20]; int ret; + uid_t uid; + user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL; cred = current_cred(); user = cred->user; + uid = from_kuid(cred->user_ns, user->uid); - kenter("%p{%u}", user, user->uid); + kenter("%p{%u}", user, uid); - if (user->uid_keyring) { + if (user->uid_keyring && user->session_keyring) { kleave(" = 0 [exist]"); return 0; } @@ -67,13 +70,13 @@ int install_user_keyrings(void) * - there may be one in existence already as it may have been * pinned by a session, but the user_struct pointing to it * may have been destroyed by setuid */ - sprintf(buf, "_uid.%u", user->uid); + sprintf(buf, "_uid.%u", uid); uid_keyring = find_keyring_by_name(buf, true); if (IS_ERR(uid_keyring)) { - uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, - cred, KEY_ALLOC_IN_QUOTA, - NULL); + uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(uid_keyring)) { ret = PTR_ERR(uid_keyring); goto error; @@ -82,13 +85,14 @@ int install_user_keyrings(void) /* get a default session keyring (which might also exist * already) */ - sprintf(buf, "_uid_ses.%u", user->uid); + sprintf(buf, "_uid_ses.%u", uid); session_keyring = find_keyring_by_name(buf, true); if (IS_ERR(session_keyring)) { session_keyring = - keyring_alloc(buf, user->uid, (gid_t) -1, - cred, KEY_ALLOC_IN_QUOTA, NULL); + keyring_alloc(buf, user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); goto error_release; @@ -129,6 +133,7 @@ int install_thread_keyring_to_cred(struct cred *new) struct key *keyring; keyring = keyring_alloc("_tid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, KEY_ALLOC_QUOTA_OVERRUN, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); @@ -169,27 +174,18 @@ static int install_thread_keyring(void) int install_process_keyring_to_cred(struct cred *new) { struct key *keyring; - int ret; - if (new->tgcred->process_keyring) + if (new->process_keyring) return -EEXIST; - keyring = keyring_alloc("_pid", new->uid, new->gid, - new, KEY_ALLOC_QUOTA_OVERRUN, NULL); + keyring = keyring_alloc("_pid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, + KEY_ALLOC_QUOTA_OVERRUN, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); - spin_lock_irq(&new->tgcred->lock); - if (!new->tgcred->process_keyring) { - new->tgcred->process_keyring = keyring; - keyring = NULL; - ret = 0; - } else { - ret = -EEXIST; - } - spin_unlock_irq(&new->tgcred->lock); - key_put(keyring); - return ret; + new->process_keyring = keyring; + return 0; } /* @@ -230,29 +226,24 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) /* create an empty session keyring */ if (!keyring) { flags = KEY_ALLOC_QUOTA_OVERRUN; - if (cred->tgcred->session_keyring) + if (cred->session_keyring) flags = KEY_ALLOC_IN_QUOTA; - keyring = keyring_alloc("_ses", cred->uid, cred->gid, - cred, flags, NULL); + keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, + flags, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); } else { - atomic_inc(&keyring->usage); + __key_get(keyring); } /* install the keyring */ - spin_lock_irq(&cred->tgcred->lock); - old = cred->tgcred->session_keyring; - rcu_assign_pointer(cred->tgcred->session_keyring, keyring); - spin_unlock_irq(&cred->tgcred->lock); - - /* we're using RCU on the pointer, but there's no point synchronising - * on it if it didn't previously point to anything */ - if (old) { - synchronize_rcu(); + old = cred->session_keyring; + rcu_assign_pointer(cred->session_keyring, keyring); + + if (old) key_put(old); - } return 0; } @@ -270,7 +261,7 @@ static int install_session_keyring(struct key *keyring) if (!new) return -ENOMEM; - ret = install_session_keyring_to_cred(new, NULL); + ret = install_session_keyring_to_cred(new, keyring); if (ret < 0) { abort_creds(new); return ret; @@ -328,10 +319,7 @@ void key_fsgid_changed(struct task_struct *tsk) * In the case of a successful return, the possession attribute is set on the * returned key reference. */ -key_ref_t search_my_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - const struct cred *cred) +key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx) { key_ref_t key_ref, ret, err; @@ -347,17 +335,14 @@ key_ref_t search_my_process_keyrings(struct key_type *type, err = ERR_PTR(-EAGAIN); /* search the thread keyring first */ - if (cred->thread_keyring) { + if (ctx->cred->thread_keyring) { key_ref = keyring_search_aux( - make_key_ref(cred->thread_keyring, 1), - cred, type, description, match); + make_key_ref(ctx->cred->thread_keyring, 1), ctx); if (!IS_ERR(key_ref)) goto found; switch (PTR_ERR(key_ref)) { case -EAGAIN: /* no key */ - if (ret) - break; case -ENOKEY: /* negative key */ ret = key_ref; break; @@ -368,10 +353,9 @@ key_ref_t search_my_process_keyrings(struct key_type *type, } /* search the process keyring second */ - if (cred->tgcred->process_keyring) { + if (ctx->cred->process_keyring) { key_ref = keyring_search_aux( - make_key_ref(cred->tgcred->process_keyring, 1), - cred, type, description, match); + make_key_ref(ctx->cred->process_keyring, 1), ctx); if (!IS_ERR(key_ref)) goto found; @@ -389,13 +373,11 @@ key_ref_t search_my_process_keyrings(struct key_type *type, } /* search the session keyring */ - if (cred->tgcred->session_keyring) { + if (ctx->cred->session_keyring) { rcu_read_lock(); key_ref = keyring_search_aux( - make_key_ref(rcu_dereference( - cred->tgcred->session_keyring), - 1), - cred, type, description, match); + make_key_ref(rcu_dereference(ctx->cred->session_keyring), 1), + ctx); rcu_read_unlock(); if (!IS_ERR(key_ref)) @@ -414,10 +396,10 @@ key_ref_t search_my_process_keyrings(struct key_type *type, } } /* or search the user-session keyring */ - else if (cred->user->session_keyring) { + else if (ctx->cred->user->session_keyring) { key_ref = keyring_search_aux( - make_key_ref(cred->user->session_keyring, 1), - cred, type, description, match); + make_key_ref(ctx->cred->user->session_keyring, 1), + ctx); if (!IS_ERR(key_ref)) goto found; @@ -449,17 +431,14 @@ found: * * Return same as search_my_process_keyrings(). */ -key_ref_t search_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - const struct cred *cred) +key_ref_t search_process_keyrings(struct keyring_search_context *ctx) { struct request_key_auth *rka; key_ref_t key_ref, ret = ERR_PTR(-EACCES), err; might_sleep(); - key_ref = search_my_process_keyrings(type, description, match, cred); + key_ref = search_my_process_keyrings(ctx); if (!IS_ERR(key_ref)) goto found; err = key_ref; @@ -468,18 +447,21 @@ key_ref_t search_process_keyrings(struct key_type *type, * search the keyrings of the process mentioned there * - we don't permit access to request_key auth keys via this method */ - if (cred->request_key_auth && - cred == current_cred() && - type != &key_type_request_key_auth + if (ctx->cred->request_key_auth && + ctx->cred == current_cred() && + ctx->index_key.type != &key_type_request_key_auth ) { + const struct cred *cred = ctx->cred; + /* defend against the auth key being revoked */ down_read(&cred->request_key_auth->sem); - if (key_validate(cred->request_key_auth) == 0) { - rka = cred->request_key_auth->payload.data; + if (key_validate(ctx->cred->request_key_auth) == 0) { + rka = ctx->cred->request_key_auth->payload.data; - key_ref = search_process_keyrings(type, description, - match, rka->cred); + ctx->cred = rka->cred; + key_ref = search_process_keyrings(ctx); + ctx->cred = cred; up_read(&cred->request_key_auth->sem); @@ -533,19 +515,23 @@ int lookup_user_key_possessed(const struct key *key, const void *target) key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, key_perm_t perm) { + struct keyring_search_context ctx = { + .match = lookup_user_key_possessed, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_LOOKUP_DIRECT), + }; struct request_key_auth *rka; - const struct cred *cred; struct key *key; key_ref_t key_ref, skey_ref; int ret; try_again: - cred = get_current_cred(); + ctx.cred = get_current_cred(); key_ref = ERR_PTR(-ENOKEY); switch (id) { case KEY_SPEC_THREAD_KEYRING: - if (!cred->thread_keyring) { + if (!ctx.cred->thread_keyring) { if (!(lflags & KEY_LOOKUP_CREATE)) goto error; @@ -557,13 +543,13 @@ try_again: goto reget_creds; } - key = cred->thread_keyring; - atomic_inc(&key->usage); + key = ctx.cred->thread_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_PROCESS_KEYRING: - if (!cred->tgcred->process_keyring) { + if (!ctx.cred->process_keyring) { if (!(lflags & KEY_LOOKUP_CREATE)) goto error; @@ -575,54 +561,64 @@ try_again: goto reget_creds; } - key = cred->tgcred->process_keyring; - atomic_inc(&key->usage); + key = ctx.cred->process_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_SESSION_KEYRING: - if (!cred->tgcred->session_keyring) { + if (!ctx.cred->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ ret = install_user_keyrings(); if (ret < 0) goto error; - ret = install_session_keyring( - cred->user->session_keyring); + if (lflags & KEY_LOOKUP_CREATE) + ret = join_session_keyring(NULL); + else + ret = install_session_keyring( + ctx.cred->user->session_keyring); if (ret < 0) goto error; goto reget_creds; + } else if (ctx.cred->session_keyring == + ctx.cred->user->session_keyring && + lflags & KEY_LOOKUP_CREATE) { + ret = join_session_keyring(NULL); + if (ret < 0) + goto error; + goto reget_creds; } rcu_read_lock(); - key = rcu_dereference(cred->tgcred->session_keyring); - atomic_inc(&key->usage); + key = rcu_dereference(ctx.cred->session_keyring); + __key_get(key); rcu_read_unlock(); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_KEYRING: - if (!cred->user->uid_keyring) { + if (!ctx.cred->user->uid_keyring) { ret = install_user_keyrings(); if (ret < 0) goto error; } - key = cred->user->uid_keyring; - atomic_inc(&key->usage); + key = ctx.cred->user->uid_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_SESSION_KEYRING: - if (!cred->user->session_keyring) { + if (!ctx.cred->user->session_keyring) { ret = install_user_keyrings(); if (ret < 0) goto error; } - key = cred->user->session_keyring; - atomic_inc(&key->usage); + key = ctx.cred->user->session_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; @@ -632,28 +628,29 @@ try_again: goto error; case KEY_SPEC_REQKEY_AUTH_KEY: - key = cred->request_key_auth; + key = ctx.cred->request_key_auth; if (!key) goto error; - atomic_inc(&key->usage); + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_REQUESTOR_KEYRING: - if (!cred->request_key_auth) + if (!ctx.cred->request_key_auth) goto error; - down_read(&cred->request_key_auth->sem); - if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) { + down_read(&ctx.cred->request_key_auth->sem); + if (test_bit(KEY_FLAG_REVOKED, + &ctx.cred->request_key_auth->flags)) { key_ref = ERR_PTR(-EKEYREVOKED); key = NULL; } else { - rka = cred->request_key_auth->payload.data; + rka = ctx.cred->request_key_auth->payload.data; key = rka->dest_keyring; - atomic_inc(&key->usage); + __key_get(key); } - up_read(&cred->request_key_auth->sem); + up_read(&ctx.cred->request_key_auth->sem); if (!key) goto error; key_ref = make_key_ref(key, 1); @@ -673,9 +670,13 @@ try_again: key_ref = make_key_ref(key, 0); /* check to see if we possess the key */ - skey_ref = search_process_keyrings(key->type, key, - lookup_user_key_possessed, - cred); + ctx.index_key.type = key->type; + ctx.index_key.description = key->description; + ctx.index_key.desc_len = strlen(key->description); + ctx.match_data = key; + kdebug("check possessed"); + skey_ref = search_process_keyrings(&ctx); + kdebug("possessed=%p", skey_ref); if (!IS_ERR(skey_ref)) { key_put(key); @@ -715,12 +716,14 @@ try_again: goto invalid_key; /* check the permissions */ - ret = key_task_permission(key_ref, cred, perm); + ret = key_task_permission(key_ref, ctx.cred, perm); if (ret < 0) goto invalid_key; + key->last_used_at = current_kernel_time().tv_sec; + error: - put_cred(cred); + put_cred(ctx.cred); return key_ref; invalid_key: @@ -731,7 +734,7 @@ invalid_key: /* if we attempted to install a keyring, then it may have caused new * creds to be installed */ reget_creds: - put_cred(cred); + put_cred(ctx.cred); goto try_again; } @@ -753,12 +756,6 @@ long join_session_keyring(const char *name) struct key *keyring; long ret, serial; - /* only permit this if there's a single thread in the thread group - - * this avoids us having to adjust the creds on all threads and risking - * ENOMEM */ - if (!current_is_single_threaded()) - return -EMLINK; - new = prepare_creds(); if (!new) return -ENOMEM; @@ -770,7 +767,7 @@ long join_session_keyring(const char *name) if (ret < 0) goto error; - serial = new->tgcred->session_keyring->serial; + serial = new->session_keyring->serial; ret = commit_creds(new); if (ret == 0) ret = serial; @@ -784,8 +781,10 @@ long join_session_keyring(const char *name) keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ - keyring = keyring_alloc(name, old->uid, old->gid, old, - KEY_ALLOC_IN_QUOTA, NULL); + keyring = keyring_alloc( + name, old->uid, old->gid, old, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK, + KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; @@ -793,6 +792,9 @@ long join_session_keyring(const char *name) } else if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; + } else if (keyring == new->session_keyring) { + ret = 0; + goto error2; } /* we've got a keyring - now to install it */ @@ -819,23 +821,16 @@ error: * Replace a process's session keyring on behalf of one of its children when * the target process is about to resume userspace execution. */ -void key_replace_session_keyring(void) +void key_change_session_keyring(struct callback_head *twork) { - const struct cred *old; - struct cred *new; - - if (!current->replacement_session_keyring) - return; - - write_lock_irq(&tasklist_lock); - new = current->replacement_session_keyring; - current->replacement_session_keyring = NULL; - write_unlock_irq(&tasklist_lock); + const struct cred *old = current_cred(); + struct cred *new = container_of(twork, struct cred, rcu); - if (!new) + if (unlikely(current->flags & PF_EXITING)) { + put_cred(new); return; + } - old = current_cred(); new-> uid = old-> uid; new-> euid = old-> euid; new-> suid = old-> suid; @@ -845,6 +840,7 @@ void key_replace_session_keyring(void) new-> sgid = old-> sgid; new->fsgid = old->fsgid; new->user = get_uid(old->user); + new->user_ns = get_user_ns(old->user_ns); new->group_info = get_group_info(old->group_info); new->securebits = old->securebits; @@ -855,10 +851,19 @@ void key_replace_session_keyring(void) new->jit_keyring = old->jit_keyring; new->thread_keyring = key_get(old->thread_keyring); - new->tgcred->tgid = old->tgcred->tgid; - new->tgcred->process_keyring = key_get(old->tgcred->process_keyring); + new->process_keyring = key_get(old->process_keyring); security_transfer_creds(new, old); commit_creds(new); } + +/* + * Make sure that root's user and user-session keyrings exist. + */ +static int __init init_root_keyring(void) +{ + return install_user_keyrings(); +} + +late_initcall(init_root_keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c index a3dc0d460de..381411941cc 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -8,7 +8,7 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * - * See Documentation/keys-request-key.txt + * See Documentation/security/keys-request-key.txt */ #include <linux/module.h> @@ -71,9 +71,8 @@ EXPORT_SYMBOL(complete_request_key); * This is called in context of freshly forked kthread before kernel_execve(), * so we can simply install the desired session_keyring at this point. */ -static int umh_keys_init(struct subprocess_info *info) +static int umh_keys_init(struct subprocess_info *info, struct cred *cred) { - struct cred *cred = (struct cred*)current_cred(); struct key *keyring = info->data; return install_session_keyring_to_cred(cred, keyring); @@ -92,17 +91,17 @@ static void umh_keys_cleanup(struct subprocess_info *info) * Call a usermode helper with a specific session keyring. */ static int call_usermodehelper_keys(char *path, char **argv, char **envp, - struct key *session_keyring, enum umh_wait wait) + struct key *session_keyring, int wait) { - gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; - struct subprocess_info *info = - call_usermodehelper_setup(path, argv, envp, gfp_mask); + struct subprocess_info *info; + info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, + umh_keys_init, umh_keys_cleanup, + session_keyring); if (!info) return -ENOMEM; - call_usermodehelper_setfns(info, umh_keys_init, umh_keys_cleanup, - key_get(session_keyring)); + key_get(session_keyring); return call_usermodehelper_exec(info, wait); } @@ -134,6 +133,7 @@ static int call_sbin_request_key(struct key_construction *cons, cred = get_current_cred(); keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, KEY_ALLOC_QUOTA_OVERRUN, NULL); put_cred(cred); if (IS_ERR(keyring)) { @@ -147,8 +147,8 @@ static int call_sbin_request_key(struct key_construction *cons, goto error_link; /* record the UID and GID */ - sprintf(uid_str, "%d", cred->fsuid); - sprintf(gid_str, "%d", cred->fsgid); + sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); + sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); @@ -158,12 +158,12 @@ static int call_sbin_request_key(struct key_construction *cons, cred->thread_keyring ? cred->thread_keyring->serial : 0); prkey = 0; - if (cred->tgcred->process_keyring) - prkey = cred->tgcred->process_keyring->serial; + if (cred->process_keyring) + prkey = cred->process_keyring->serial; sprintf(keyring_str[1], "%d", prkey); rcu_read_lock(); - session = rcu_dereference(cred->tgcred->session_keyring); + session = rcu_dereference(cred->session_keyring); if (!session) session = cred->user->session_keyring; sskey = session->serial; @@ -305,14 +305,14 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - dest_keyring = key_get(cred->tgcred->process_keyring); + dest_keyring = key_get(cred->process_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_SESSION_KEYRING: rcu_read_lock(); dest_keyring = key_get( - rcu_dereference(cred->tgcred->session_keyring)); + rcu_dereference(cred->session_keyring)); rcu_read_unlock(); if (dest_keyring) @@ -345,34 +345,42 @@ static void construct_get_dest_keyring(struct key **_dest_keyring) * May return a key that's already under construction instead if there was a * race between two thread calling request_key(). */ -static int construct_alloc_key(struct key_type *type, - const char *description, +static int construct_alloc_key(struct keyring_search_context *ctx, struct key *dest_keyring, unsigned long flags, struct key_user *user, struct key **_key) { - const struct cred *cred = current_cred(); - unsigned long prealloc; + struct assoc_array_edit *edit; struct key *key; + key_perm_t perm; key_ref_t key_ref; int ret; - kenter("%s,%s,,,", type->name, description); + kenter("%s,%s,,,", + ctx->index_key.type->name, ctx->index_key.description); *_key = NULL; mutex_lock(&user->cons_lock); - key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred, - KEY_POS_ALL, flags); + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW; + if (ctx->index_key.type->read) + perm |= KEY_POS_READ; + if (ctx->index_key.type == &key_type_keyring || + ctx->index_key.type->update) + perm |= KEY_POS_WRITE; + + key = key_alloc(ctx->index_key.type, ctx->index_key.description, + ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, + perm, flags); if (IS_ERR(key)) goto alloc_failed; set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); if (dest_keyring) { - ret = __key_link_begin(dest_keyring, type, description, - &prealloc); + ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); if (ret < 0) goto link_prealloc_failed; } @@ -382,16 +390,16 @@ static int construct_alloc_key(struct key_type *type, * waited for locks */ mutex_lock(&key_construction_mutex); - key_ref = search_process_keyrings(type, description, type->match, cred); + key_ref = search_process_keyrings(ctx); if (!IS_ERR(key_ref)) goto key_already_present; if (dest_keyring) - __key_link(dest_keyring, key, &prealloc); + __key_link(key, &edit); mutex_unlock(&key_construction_mutex); if (dest_keyring) - __key_link_end(dest_keyring, type, prealloc); + __key_link_end(dest_keyring, &ctx->index_key, edit); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); @@ -406,8 +414,8 @@ key_already_present: if (dest_keyring) { ret = __key_link_check_live_key(dest_keyring, key); if (ret == 0) - __key_link(dest_keyring, key, &prealloc); - __key_link_end(dest_keyring, type, prealloc); + __key_link(key, &edit); + __key_link_end(dest_keyring, &ctx->index_key, edit); if (ret < 0) goto link_check_failed; } @@ -436,8 +444,7 @@ alloc_failed: /* * Commence key construction. */ -static struct key *construct_key_and_link(struct key_type *type, - const char *description, +static struct key *construct_key_and_link(struct keyring_search_context *ctx, const char *callout_info, size_t callout_len, void *aux, @@ -450,14 +457,13 @@ static struct key *construct_key_and_link(struct key_type *type, kenter(""); - user = key_user_lookup(current_fsuid(), current_user_ns()); + user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); construct_get_dest_keyring(&dest_keyring); - ret = construct_alloc_key(type, description, dest_keyring, flags, user, - &key); + ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); key_user_put(user); if (ret == 0) { @@ -470,7 +476,7 @@ static struct key *construct_key_and_link(struct key_type *type, } else if (ret == -EINPROGRESS) { ret = 0; } else { - key = ERR_PTR(ret); + goto couldnt_alloc_key; } key_put(dest_keyring); @@ -480,6 +486,7 @@ static struct key *construct_key_and_link(struct key_type *type, construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key); +couldnt_alloc_key: key_put(dest_keyring); kleave(" = %d", ret); return ERR_PTR(ret); @@ -520,18 +527,24 @@ struct key *request_key_and_link(struct key_type *type, struct key *dest_keyring, unsigned long flags) { - const struct cred *cred = current_cred(); + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.description = description, + .cred = current_cred(), + .match = type->match, + .match_data = description, + .flags = KEYRING_SEARCH_LOOKUP_DIRECT, + }; struct key *key; key_ref_t key_ref; int ret; kenter("%s,%s,%p,%zu,%p,%p,%lx", - type->name, description, callout_info, callout_len, aux, - dest_keyring, flags); + ctx.index_key.type->name, ctx.index_key.description, + callout_info, callout_len, aux, dest_keyring, flags); /* search all the process keyrings for a key */ - key_ref = search_process_keyrings(type, description, type->match, - cred); + key_ref = search_process_keyrings(&ctx); if (!IS_ERR(key_ref)) { key = key_ref_to_ptr(key_ref); @@ -554,9 +567,8 @@ struct key *request_key_and_link(struct key_type *type, if (!callout_info) goto error; - key = construct_key_and_link(type, description, callout_info, - callout_len, aux, dest_keyring, - flags); + key = construct_key_and_link(&ctx, callout_info, callout_len, + aux, dest_keyring, flags); } error: @@ -584,8 +596,10 @@ int wait_for_key_construction(struct key *key, bool intr) intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); if (ret < 0) return ret; - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) - return -ENOKEY; + if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { + smp_rmb(); + return key->type_data.reject_error; + } return key_validate(key); } EXPORT_SYMBOL(wait_for_key_construction); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index 68164031a74..7495a93b4b9 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -8,7 +8,7 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * - * See Documentation/keys-request-key.txt + * See Documentation/security/keys-request-key.txt */ #include <linux/module.h> @@ -18,8 +18,10 @@ #include <linux/slab.h> #include <asm/uaccess.h> #include "internal.h" +#include <keys/user-type.h> -static int request_key_auth_instantiate(struct key *, const void *, size_t); +static int request_key_auth_instantiate(struct key *, + struct key_preparsed_payload *); static void request_key_auth_describe(const struct key *, struct seq_file *); static void request_key_auth_revoke(struct key *); static void request_key_auth_destroy(struct key *); @@ -42,10 +44,9 @@ struct key_type key_type_request_key_auth = { * Instantiate a request-key authorisation key. */ static int request_key_auth_instantiate(struct key *key, - const void *data, - size_t datalen) + struct key_preparsed_payload *prep) { - key->payload.data = (struct request_key_auth *) data; + key->payload.data = (struct request_key_auth *)prep->data; return 0; } @@ -59,7 +60,8 @@ static void request_key_auth_describe(const struct key *key, seq_puts(m, "key:"); seq_puts(m, key->description); - seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); + if (key_is_instantiated(key)) + seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); } /* @@ -221,35 +223,31 @@ error_alloc: } /* - * See if an authorisation key is associated with a particular key. - */ -static int key_get_instantiation_authkey_match(const struct key *key, - const void *_id) -{ - struct request_key_auth *rka = key->payload.data; - key_serial_t id = (key_serial_t)(unsigned long) _id; - - return rka->target_key->serial == id; -} - -/* * Search the current process's keyrings for the authorisation key for * instantiation of a key. */ struct key *key_get_instantiation_authkey(key_serial_t target_id) { - const struct cred *cred = current_cred(); + char description[16]; + struct keyring_search_context ctx = { + .index_key.type = &key_type_request_key_auth, + .index_key.description = description, + .cred = current_cred(), + .match = user_match, + .match_data = description, + .flags = KEYRING_SEARCH_LOOKUP_DIRECT, + }; struct key *authkey; key_ref_t authkey_ref; - authkey_ref = search_process_keyrings( - &key_type_request_key_auth, - (void *) (unsigned long) target_id, - key_get_instantiation_authkey_match, - cred); + sprintf(description, "%x", target_id); + + authkey_ref = search_process_keyrings(&ctx); if (IS_ERR(authkey_ref)) { authkey = ERR_CAST(authkey_ref); + if (authkey == ERR_PTR(-EAGAIN)) + authkey = ERR_PTR(-ENOKEY); goto error; } diff --git a/security/keys/sysctl.c b/security/keys/sysctl.c index ee32d181764..b68faa1a5cf 100644 --- a/security/keys/sysctl.c +++ b/security/keys/sysctl.c @@ -15,7 +15,7 @@ static const int zero, one = 1, max = INT_MAX; -ctl_table key_sysctls[] = { +struct ctl_table key_sysctls[] = { { .procname = "maxkeys", .data = &key_quota_maxkeys, @@ -61,5 +61,16 @@ ctl_table key_sysctls[] = { .extra1 = (void *) &zero, .extra2 = (void *) &max, }, +#ifdef CONFIG_PERSISTENT_KEYRINGS + { + .procname = "persistent_keyring_expiry", + .data = &persistent_keyring_expiry, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &zero, + .extra2 = (void *) &max, + }, +#endif { } }; diff --git a/security/keys/trusted.c b/security/keys/trusted.c index 83fc92e297c..6b804aa4529 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -8,7 +8,7 @@ * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2 of the License. * - * See Documentation/keys-trusted-encrypted.txt + * See Documentation/security/keys-trusted-encrypted.txt */ #include <linux/uaccess.h> @@ -369,38 +369,6 @@ static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, } /* - * get a random value from TPM - */ -static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) -{ - int ret; - - INIT_BUF(tb); - store16(tb, TPM_TAG_RQU_COMMAND); - store32(tb, TPM_GETRANDOM_SIZE); - store32(tb, TPM_ORD_GETRANDOM); - store32(tb, len); - ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); - if (!ret) - memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); - return ret; -} - -static int my_get_random(unsigned char *buf, int len) -{ - struct tpm_buf *tb; - int ret; - - tb = kmalloc(sizeof *tb, GFP_KERNEL); - if (!tb) - return -ENOMEM; - ret = tpm_get_random(tb, buf, len); - - kfree(tb); - return ret; -} - -/* * Lock a trusted key, by extending a selected PCR. * * Prevents a trusted key that is sealed to PCRs from being accessed. @@ -413,8 +381,8 @@ static int pcrlock(const int pcrnum) if (!capable(CAP_SYS_ADMIN)) return -EPERM; - ret = my_get_random(hash, SHA1_DIGEST_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); + if (ret != SHA1_DIGEST_SIZE) return ret; return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; } @@ -429,8 +397,8 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, unsigned char ononce[TPM_NONCE_SIZE]; int ret; - ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) return ret; INIT_BUF(tb); @@ -524,8 +492,8 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, if (ret < 0) goto out; - ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) goto out; ordinal = htonl(TPM_ORD_SEAL); datsize = htonl(datalen); @@ -634,8 +602,8 @@ static int tpm_unseal(struct tpm_buf *tb, ordinal = htonl(TPM_ORD_UNSEAL); keyhndl = htonl(SRKHANDLE); - ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); - if (ret < 0) { + ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) { pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); return ret; } @@ -779,10 +747,13 @@ static int getoptions(char *c, struct trusted_key_payload *pay, opt->pcrinfo_len = strlen(args[0].from) / 2; if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) return -EINVAL; - hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len); + res = hex2bin(opt->pcrinfo, args[0].from, + opt->pcrinfo_len); + if (res < 0) + return -EINVAL; break; case Opt_keyhandle: - res = strict_strtoul(args[0].from, 16, &handle); + res = kstrtoul(args[0].from, 16, &handle); if (res < 0) return -EINVAL; opt->keytype = SEAL_keytype; @@ -791,12 +762,18 @@ static int getoptions(char *c, struct trusted_key_payload *pay, case Opt_keyauth: if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) return -EINVAL; - hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE); + res = hex2bin(opt->keyauth, args[0].from, + SHA1_DIGEST_SIZE); + if (res < 0) + return -EINVAL; break; case Opt_blobauth: if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) return -EINVAL; - hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE); + res = hex2bin(opt->blobauth, args[0].from, + SHA1_DIGEST_SIZE); + if (res < 0) + return -EINVAL; break; case Opt_migratable: if (*args[0].from == '0') @@ -805,7 +782,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return -EINVAL; break; case Opt_pcrlock: - res = strict_strtoul(args[0].from, 10, &lock); + res = kstrtoul(args[0].from, 10, &lock); if (res < 0) return -EINVAL; opt->pcrlock = lock; @@ -843,7 +820,7 @@ static int datablob_parse(char *datablob, struct trusted_key_payload *p, c = strsep(&datablob, " \t"); if (!c) return -EINVAL; - ret = strict_strtol(c, 10, &keylen); + ret = kstrtol(c, 10, &keylen); if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) return -EINVAL; p->key_len = keylen; @@ -860,7 +837,9 @@ static int datablob_parse(char *datablob, struct trusted_key_payload *p, p->blob_len = strlen(c) / 2; if (p->blob_len > MAX_BLOB_SIZE) return -EINVAL; - hex2bin(p->blob, c, p->blob_len); + ret = hex2bin(p->blob, c, p->blob_len); + if (ret < 0) + return -EINVAL; ret = getoptions(datablob, p, o); if (ret < 0) return ret; @@ -916,22 +895,24 @@ static struct trusted_key_payload *trusted_payload_alloc(struct key *key) * * On success, return 0. Otherwise return errno. */ -static int trusted_instantiate(struct key *key, const void *data, - size_t datalen) +static int trusted_instantiate(struct key *key, + struct key_preparsed_payload *prep) { struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL; + size_t datalen = prep->datalen; char *datablob; int ret = 0; int key_cmd; + size_t key_len; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; datablob = kmalloc(datalen + 1, GFP_KERNEL); if (!datablob) return -ENOMEM; - memcpy(datablob, data, datalen); + memcpy(datablob, prep->data, datalen); datablob[datalen] = '\0'; options = trusted_options_alloc(); @@ -963,8 +944,9 @@ static int trusted_instantiate(struct key *key, const void *data, pr_info("trusted_key: key_unseal failed (%d)\n", ret); break; case Opt_new: - ret = my_get_random(payload->key, payload->key_len); - if (ret < 0) { + key_len = payload->key_len; + ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); + if (ret != key_len) { pr_info("trusted_key: key_create failed (%d)\n", ret); goto out; } @@ -982,7 +964,7 @@ out: kfree(datablob); kfree(options); if (!ret) - rcu_assign_pointer(key->payload.data, payload); + rcu_assign_keypointer(key, payload); else kfree(payload); return ret; @@ -1000,17 +982,18 @@ static void trusted_rcu_free(struct rcu_head *rcu) /* * trusted_update - reseal an existing key with new PCR values */ -static int trusted_update(struct key *key, const void *data, size_t datalen) +static int trusted_update(struct key *key, struct key_preparsed_payload *prep) { struct trusted_key_payload *p = key->payload.data; struct trusted_key_payload *new_p; struct trusted_key_options *new_o; + size_t datalen = prep->datalen; char *datablob; int ret = 0; if (!p->migratable) return -EPERM; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; datablob = kmalloc(datalen + 1, GFP_KERNEL); @@ -1027,7 +1010,7 @@ static int trusted_update(struct key *key, const void *data, size_t datalen) goto out; } - memcpy(datablob, data, datalen); + memcpy(datablob, prep->data, datalen); datablob[datalen] = '\0'; ret = datablob_parse(datablob, new_p, new_o); if (ret != Opt_update) { @@ -1056,7 +1039,7 @@ static int trusted_update(struct key *key, const void *data, size_t datalen) goto out; } } - rcu_assign_pointer(key->payload.data, new_p); + rcu_assign_keypointer(key, new_p); call_rcu(&p->rcu, trusted_rcu_free); out: kfree(datablob); @@ -1076,8 +1059,7 @@ static long trusted_read(const struct key *key, char __user *buffer, char *bufp; int i; - p = rcu_dereference_protected(key->payload.data, - rwsem_is_locked(&((struct key *)key)->sem)); + p = rcu_dereference_key(key); if (!p) return -EINVAL; if (!buffer || buflen <= 0) @@ -1088,7 +1070,7 @@ static long trusted_read(const struct key *key, char __user *buffer, bufp = ascii_buf; for (i = 0; i < p->blob_len; i++) - bufp = pack_hex_byte(bufp, p->blob[i]); + bufp = hex_byte_pack(bufp, p->blob[i]); if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { kfree(ascii_buf); return -EFAULT; diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 02807fb1634..faa2caeb593 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -18,33 +18,56 @@ #include <asm/uaccess.h> #include "internal.h" +static int logon_vet_description(const char *desc); + /* * user defined keys take an arbitrary string as the description and an * arbitrary blob of data as the payload */ struct key_type key_type_user = { - .name = "user", - .instantiate = user_instantiate, - .update = user_update, - .match = user_match, - .revoke = user_revoke, - .destroy = user_destroy, - .describe = user_describe, - .read = user_read, + .name = "user", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = user_instantiate, + .update = user_update, + .match = user_match, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .read = user_read, }; EXPORT_SYMBOL_GPL(key_type_user); /* + * This key type is essentially the same as key_type_user, but it does + * not define a .read op. This is suitable for storing username and + * password pairs in the keyring that you do not want to be readable + * from userspace. + */ +struct key_type key_type_logon = { + .name = "logon", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = user_instantiate, + .update = user_update, + .match = user_match, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .vet_description = logon_vet_description, +}; +EXPORT_SYMBOL_GPL(key_type_logon); + +/* * instantiate a user defined key */ -int user_instantiate(struct key *key, const void *data, size_t datalen) +int user_instantiate(struct key *key, struct key_preparsed_payload *prep) { struct user_key_payload *upayload; + size_t datalen = prep->datalen; int ret; ret = -EINVAL; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) goto error; ret = key_payload_reserve(key, datalen); @@ -58,8 +81,8 @@ int user_instantiate(struct key *key, const void *data, size_t datalen) /* attach the data */ upayload->datalen = datalen; - memcpy(upayload->data, data, datalen); - rcu_assign_pointer(key->payload.data, upayload); + memcpy(upayload->data, prep->data, datalen); + rcu_assign_keypointer(key, upayload); ret = 0; error: @@ -69,28 +92,17 @@ error: EXPORT_SYMBOL_GPL(user_instantiate); /* - * dispose of the old data from an updated user defined key - */ -static void user_update_rcu_disposal(struct rcu_head *rcu) -{ - struct user_key_payload *upayload; - - upayload = container_of(rcu, struct user_key_payload, rcu); - - kfree(upayload); -} - -/* * update a user defined key * - the key's semaphore is write-locked */ -int user_update(struct key *key, const void *data, size_t datalen) +int user_update(struct key *key, struct key_preparsed_payload *prep) { struct user_key_payload *upayload, *zap; + size_t datalen = prep->datalen; int ret; ret = -EINVAL; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) goto error; /* construct a replacement payload */ @@ -100,7 +112,7 @@ int user_update(struct key *key, const void *data, size_t datalen) goto error; upayload->datalen = datalen; - memcpy(upayload->data, data, datalen); + memcpy(upayload->data, prep->data, datalen); /* check the quota and attach the new data */ zap = upayload; @@ -110,11 +122,12 @@ int user_update(struct key *key, const void *data, size_t datalen) if (ret == 0) { /* attach the new data, displacing the old */ zap = key->payload.data; - rcu_assign_pointer(key->payload.data, upayload); + rcu_assign_keypointer(key, upayload); key->expiry = 0; } - call_rcu(&zap->rcu, user_update_rcu_disposal); + if (zap) + kfree_rcu(zap, rcu); error: return ret; @@ -144,8 +157,8 @@ void user_revoke(struct key *key) key_payload_reserve(key, 0); if (upayload) { - rcu_assign_pointer(key->payload.data, NULL); - call_rcu(&upayload->rcu, user_update_rcu_disposal); + rcu_assign_keypointer(key, NULL); + kfree_rcu(upayload, rcu); } } @@ -169,8 +182,8 @@ EXPORT_SYMBOL_GPL(user_destroy); void user_describe(const struct key *key, struct seq_file *m) { seq_puts(m, key->description); - - seq_printf(m, ": %u", key->datalen); + if (key_is_instantiated(key)) + seq_printf(m, ": %u", key->datalen); } EXPORT_SYMBOL_GPL(user_describe); @@ -184,8 +197,7 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen) struct user_key_payload *upayload; long ret; - upayload = rcu_dereference_protected( - key->payload.data, rwsem_is_locked(&((struct key *)key)->sem)); + upayload = rcu_dereference_key(key); ret = upayload->datalen; /* we can return the data as is */ @@ -201,3 +213,20 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen) } EXPORT_SYMBOL_GPL(user_read); + +/* Vet the description for a "logon" key */ +static int logon_vet_description(const char *desc) +{ + char *p; + + /* require a "qualified" description string */ + p = strchr(desc, ':'); + if (!p) + return -EINVAL; + + /* also reject description with ':' as first char */ + if (p == desc) + return -EINVAL; + + return 0; +} |