From 295c896cb95de18004ef5e1b53f44c2ad001f936 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 22 Jan 2009 10:50:50 +0300 Subject: fs/Kconfig: move ecryptfs out Signed-off-by: Alexey Dobriyan --- fs/ecryptfs/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) create mode 100644 fs/ecryptfs/Kconfig (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/Kconfig b/fs/ecryptfs/Kconfig new file mode 100644 index 00000000000..0c754e64232 --- /dev/null +++ b/fs/ecryptfs/Kconfig @@ -0,0 +1,11 @@ +config ECRYPT_FS + tristate "eCrypt filesystem layer support (EXPERIMENTAL)" + depends on EXPERIMENTAL && KEYS && CRYPTO && NET + help + Encrypted filesystem that operates on the VFS layer. See + to learn more about + eCryptfs. Userspace components are required and can be + obtained from . + + To compile this file system support as a module, choose M here: the + module will be called ecryptfs. -- cgit v1.2.3-18-g5258 From fd9fc842bbab0cb5560b0d52ce4598c898707863 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Fri, 6 Feb 2009 18:06:51 -0600 Subject: eCryptfs: Regression in unencrypted filename symlinks The addition of filename encryption caused a regression in unencrypted filename symlink support. ecryptfs_copy_filename() is used when dealing with unencrypted filenames and it reported that the new, copied filename was a character longer than it should have been. This caused the return value of readlink() to count the NULL byte of the symlink target. Most applications don't care about the extra NULL byte, but a version control system (bzr) helped in discovering the bug. Signed-off-by: Tyler Hicks Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index c01e043670e..f6caeb1d110 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1716,7 +1716,7 @@ static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size, { int rc = 0; - (*copied_name) = kmalloc((name_size + 2), GFP_KERNEL); + (*copied_name) = kmalloc((name_size + 1), GFP_KERNEL); if (!(*copied_name)) { rc = -ENOMEM; goto out; @@ -1726,7 +1726,7 @@ static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size, * in printing out the * string in debug * messages */ - (*copied_name_size) = (name_size + 1); + (*copied_name_size) = name_size; out: return rc; } -- cgit v1.2.3-18-g5258 From 84814d642a4f1f294bd675ab11aae1ca54c6cedb Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Fri, 13 Mar 2009 13:51:59 -0700 Subject: eCryptfs: don't encrypt file key with filename key eCryptfs has file encryption keys (FEK), file encryption key encryption keys (FEKEK), and filename encryption keys (FNEK). The per-file FEK is encrypted with one or more FEKEKs and stored in the header of the encrypted file. I noticed that the FEK is also being encrypted by the FNEK. This is a problem if a user wants to use a different FNEK than their FEKEK, as their file contents will still be accessible with the FNEK. This is a minimalistic patch which prevents the FNEKs signatures from being copied to the inode signatures list. Ultimately, it keeps the FEK from being encrypted with a FNEK. Signed-off-by: Tyler Hicks Cc: Serge Hallyn Acked-by: Dustin Kirkland Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 2 ++ fs/ecryptfs/ecryptfs_kernel.h | 3 ++- fs/ecryptfs/keystore.c | 3 ++- fs/ecryptfs/main.c | 5 +++-- 4 files changed, 9 insertions(+), 4 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index f6caeb1d110..bdca1f4b3a3 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -946,6 +946,8 @@ static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( list_for_each_entry(global_auth_tok, &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { + if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK) + continue; rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); if (rc) { printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index c11fc95714a..eb2267eca1f 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -328,6 +328,7 @@ struct ecryptfs_dentry_info { */ struct ecryptfs_global_auth_tok { #define ECRYPTFS_AUTH_TOK_INVALID 0x00000001 +#define ECRYPTFS_AUTH_TOK_FNEK 0x00000002 u32 flags; struct list_head mount_crypt_stat_list; struct key *global_auth_tok_key; @@ -696,7 +697,7 @@ ecryptfs_write_header_metadata(char *virt, int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig); int ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, - char *sig); + char *sig, u32 global_auth_tok_flags); int ecryptfs_get_global_auth_tok_for_sig( struct ecryptfs_global_auth_tok **global_auth_tok, struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig); diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index ff539420cc6..e4a6223c314 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -2375,7 +2375,7 @@ struct kmem_cache *ecryptfs_global_auth_tok_cache; int ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, - char *sig) + char *sig, u32 global_auth_tok_flags) { struct ecryptfs_global_auth_tok *new_auth_tok; int rc = 0; @@ -2389,6 +2389,7 @@ ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, goto out; } memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); + new_auth_tok->flags = global_auth_tok_flags; new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); list_add(&new_auth_tok->mount_crypt_stat_list, diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 789cf2e1be1..aed56c25539 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -319,7 +319,7 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) case ecryptfs_opt_ecryptfs_sig: sig_src = args[0].from; rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, - sig_src); + sig_src, 0); if (rc) { printk(KERN_ERR "Error attempting to register " "global sig; rc = [%d]\n", rc); @@ -370,7 +370,8 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) ECRYPTFS_SIG_SIZE_HEX] = '\0'; rc = ecryptfs_add_global_auth_tok( mount_crypt_stat, - mount_crypt_stat->global_default_fnek_sig); + mount_crypt_stat->global_default_fnek_sig, + ECRYPTFS_AUTH_TOK_FNEK); if (rc) { printk(KERN_ERR "Error attempting to register " "global fnek sig [%s]; rc = [%d]\n", -- cgit v1.2.3-18-g5258 From 8faece5f906725c10e7a1f6caf84452abadbdc7b Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Fri, 20 Mar 2009 01:25:09 -0500 Subject: eCryptfs: Allocate a variable number of pages for file headers When allocating the memory used to store the eCryptfs header contents, a single, zeroed page was being allocated with get_zeroed_page(). However, the size of an eCryptfs header is either PAGE_CACHE_SIZE or ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE (8192), whichever is larger, and is stored in the file's private_data->crypt_stat->num_header_bytes_at_front field. ecryptfs_write_metadata_to_contents() was using num_header_bytes_at_front to decide how many bytes should be written to the lower filesystem for the file header. Unfortunately, at least 8K was being written from the page, despite the chance of the single, zeroed page being smaller than 8K. This resulted in random areas of kernel memory being written between the 0x1000 and 0x1FFF bytes offsets in the eCryptfs file headers if PAGE_SIZE was 4K. This patch allocates a variable number of pages, calculated with num_header_bytes_at_front, and passes the number of allocated pages along to ecryptfs_write_metadata_to_contents(). Thanks to Florian Streibelt for reporting the data leak and working with me to find the problem. 2.6.28 is the only kernel release with this vulnerability. Corresponds to CVE-2009-0787 Signed-off-by: Tyler Hicks Acked-by: Dustin Kirkland Reviewed-by: Eric Sandeen Reviewed-by: Eugene Teo Cc: Greg KH Cc: dann frazier Cc: Serge E. Hallyn Cc: Florian Streibelt Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index bdca1f4b3a3..75bee99de0f 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1324,14 +1324,13 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t max, } static int -ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, - struct dentry *ecryptfs_dentry, - char *virt) +ecryptfs_write_metadata_to_contents(struct dentry *ecryptfs_dentry, + char *virt, size_t virt_len) { int rc; rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt, - 0, crypt_stat->num_header_bytes_at_front); + 0, virt_len); if (rc) printk(KERN_ERR "%s: Error attempting to write header " "information to lower file; rc = [%d]\n", __func__, @@ -1341,7 +1340,6 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, static int ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, - struct ecryptfs_crypt_stat *crypt_stat, char *page_virt, size_t size) { int rc; @@ -1351,6 +1349,17 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, return rc; } +static unsigned long ecryptfs_get_zeroed_pages(gfp_t gfp_mask, + unsigned int order) +{ + struct page *page; + + page = alloc_pages(gfp_mask | __GFP_ZERO, order); + if (page) + return (unsigned long) page_address(page); + return 0; +} + /** * ecryptfs_write_metadata * @ecryptfs_dentry: The eCryptfs dentry @@ -1367,7 +1376,9 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) { struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; + unsigned int order; char *virt; + size_t virt_len; size_t size = 0; int rc = 0; @@ -1383,33 +1394,35 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) rc = -EINVAL; goto out; } + virt_len = crypt_stat->num_header_bytes_at_front; + order = get_order(virt_len); /* Released in this function */ - virt = (char *)get_zeroed_page(GFP_KERNEL); + virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order); if (!virt) { printk(KERN_ERR "%s: Out of memory\n", __func__); rc = -ENOMEM; goto out; } - rc = ecryptfs_write_headers_virt(virt, PAGE_CACHE_SIZE, &size, - crypt_stat, ecryptfs_dentry); + rc = ecryptfs_write_headers_virt(virt, virt_len, &size, crypt_stat, + ecryptfs_dentry); if (unlikely(rc)) { printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", __func__, rc); goto out_free; } if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) - rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, - crypt_stat, virt, size); + rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, virt, + size); else - rc = ecryptfs_write_metadata_to_contents(crypt_stat, - ecryptfs_dentry, virt); + rc = ecryptfs_write_metadata_to_contents(ecryptfs_dentry, virt, + virt_len); if (rc) { printk(KERN_ERR "%s: Error writing metadata out to lower file; " "rc = [%d]\n", __func__, rc); goto out_free; } out_free: - free_page((unsigned long)virt); + free_pages((unsigned long)virt, order); out: return rc; } -- cgit v1.2.3-18-g5258 From 2aac0cf88681bfa092f731553bc7fbd23516be73 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Fri, 20 Mar 2009 02:23:57 -0500 Subject: eCryptfs: NULL crypt_stat dereference during lookup If ecryptfs_encrypted_view or ecryptfs_xattr_metadata were being specified as mount options, a NULL pointer dereference of crypt_stat was possible during lookup. This patch moves the crypt_stat assignment into ecryptfs_lookup_and_interpose_lower(), ensuring that crypt_stat will not be NULL before we attempt to dereference it. Thanks to Dan Carpenter and his static analysis tool, smatch, for finding this bug. Signed-off-by: Tyler Hicks Acked-by: Dustin Kirkland Cc: Dan Carpenter Cc: Serge Hallyn Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 10 ++++++---- fs/ecryptfs/ecryptfs_kernel.h | 1 - fs/ecryptfs/inode.c | 32 ++++++++++++-------------------- 3 files changed, 18 insertions(+), 25 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 75bee99de0f..8b65f289ee0 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -2221,17 +2221,19 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, struct dentry *ecryptfs_dir_dentry, const char *name, size_t name_size) { + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = + &ecryptfs_superblock_to_private( + ecryptfs_dir_dentry->d_sb)->mount_crypt_stat; char *decoded_name; size_t decoded_name_size; size_t packet_size; int rc = 0; - if ((name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) + if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) + && !(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) + && (name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) && (strncmp(name, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) == 0)) { - struct ecryptfs_mount_crypt_stat *mount_crypt_stat = - &ecryptfs_superblock_to_private( - ecryptfs_dir_dentry->d_sb)->mount_crypt_stat; const char *orig_name = name; size_t orig_name_size = name_size; diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index eb2267eca1f..ac749d4d644 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -620,7 +620,6 @@ int ecryptfs_interpose(struct dentry *hidden_dentry, u32 flags); int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct dentry *lower_dentry, - struct ecryptfs_crypt_stat *crypt_stat, struct inode *ecryptfs_dir_inode, struct nameidata *ecryptfs_nd); int ecryptfs_decode_and_decrypt_filename(char **decrypted_name, diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 5697899a168..55b3145b807 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -246,7 +246,6 @@ out: */ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct dentry *lower_dentry, - struct ecryptfs_crypt_stat *crypt_stat, struct inode *ecryptfs_dir_inode, struct nameidata *ecryptfs_nd) { @@ -254,6 +253,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct vfsmount *lower_mnt; struct inode *lower_inode; struct ecryptfs_mount_crypt_stat *mount_crypt_stat; + struct ecryptfs_crypt_stat *crypt_stat; char *page_virt = NULL; u64 file_size; int rc = 0; @@ -314,6 +314,11 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, goto out_free_kmem; } } + crypt_stat = &ecryptfs_inode_to_private( + ecryptfs_dentry->d_inode)->crypt_stat; + /* TODO: lock for crypt_stat comparison */ + if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) + ecryptfs_set_default_sizes(crypt_stat); rc = ecryptfs_read_and_validate_header_region(page_virt, ecryptfs_dentry->d_inode); if (rc) { @@ -362,9 +367,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, { char *encrypted_and_encoded_name = NULL; size_t encrypted_and_encoded_name_size; - struct ecryptfs_crypt_stat *crypt_stat = NULL; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL; - struct ecryptfs_inode_info *inode_info; struct dentry *lower_dir_dentry, *lower_dentry; int rc = 0; @@ -388,26 +391,15 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, } if (lower_dentry->d_inode) goto lookup_and_interpose; - inode_info = ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); - if (inode_info) { - crypt_stat = &inode_info->crypt_stat; - /* TODO: lock for crypt_stat comparison */ - if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) - ecryptfs_set_default_sizes(crypt_stat); - } - if (crypt_stat) - mount_crypt_stat = crypt_stat->mount_crypt_stat; - else - mount_crypt_stat = &ecryptfs_superblock_to_private( - ecryptfs_dentry->d_sb)->mount_crypt_stat; - if (!(crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES)) - && !(mount_crypt_stat && (mount_crypt_stat->flags - & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) + mount_crypt_stat = &ecryptfs_superblock_to_private( + ecryptfs_dentry->d_sb)->mount_crypt_stat; + if (!(mount_crypt_stat + && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) goto lookup_and_interpose; dput(lower_dentry); rc = ecryptfs_encrypt_and_encode_filename( &encrypted_and_encoded_name, &encrypted_and_encoded_name_size, - crypt_stat, mount_crypt_stat, ecryptfs_dentry->d_name.name, + NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name, ecryptfs_dentry->d_name.len); if (rc) { printk(KERN_ERR "%s: Error attempting to encrypt and encode " @@ -426,7 +418,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, } lookup_and_interpose: rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry, - crypt_stat, ecryptfs_dir_inode, + ecryptfs_dir_inode, ecryptfs_nd); goto out; out_d_drop: -- cgit v1.2.3-18-g5258