aboutsummaryrefslogtreecommitdiff
path: root/security/keys
diff options
context:
space:
mode:
Diffstat (limited to 'security/keys')
-rw-r--r--security/keys/internal.h17
-rw-r--r--security/keys/key.c25
-rw-r--r--security/keys/keyctl.c95
-rw-r--r--security/keys/keyring.c14
-rw-r--r--security/keys/permission.c24
-rw-r--r--security/keys/proc.c8
-rw-r--r--security/keys/process_keys.c333
-rw-r--r--security/keys/request_key.c29
-rw-r--r--security/keys/request_key_auth.c41
9 files changed, 317 insertions, 269 deletions
diff --git a/security/keys/internal.h b/security/keys/internal.h
index d1586c62978..81932abefe7 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -12,6 +12,7 @@
#ifndef _INTERNAL_H
#define _INTERNAL_H
+#include <linux/sched.h>
#include <linux/key-type.h>
static inline __attribute__((format(printf, 1, 2)))
@@ -25,7 +26,7 @@ void no_printk(const char *fmt, ...)
#define kleave(FMT, ...) \
printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
- printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
+ printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__)
#else
#define kenter(FMT, ...) \
no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
@@ -97,7 +98,7 @@ extern struct key *keyring_search_instkey(struct key *keyring,
typedef int (*key_match_func_t)(const struct key *, const void *);
extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
- struct task_struct *tsk,
+ const struct cred *cred,
struct key_type *type,
const void *description,
key_match_func_t match);
@@ -105,13 +106,13 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
extern key_ref_t search_process_keyrings(struct key_type *type,
const void *description,
key_match_func_t match,
- struct task_struct *tsk);
+ const struct cred *cred);
extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
extern int install_user_keyrings(void);
-extern int install_thread_keyring(void);
-extern int install_process_keyring(void);
+extern int install_thread_keyring_to_cred(struct cred *);
+extern int install_process_keyring_to_cred(struct cred *);
extern struct key *request_key_and_link(struct key_type *type,
const char *description,
@@ -130,12 +131,12 @@ extern long join_session_keyring(const char *name);
* check to see whether permission is granted to use a key in the desired way
*/
extern int key_task_permission(const key_ref_t key_ref,
- struct task_struct *context,
+ const struct cred *cred,
key_perm_t perm);
static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
{
- return key_task_permission(key_ref, current, perm);
+ return key_task_permission(key_ref, current_cred(), perm);
}
/* required permissions */
@@ -153,7 +154,7 @@ static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
struct request_key_auth {
struct key *target_key;
struct key *dest_keyring;
- struct task_struct *context;
+ const struct cred *cred;
void *callout_info;
size_t callout_len;
pid_t pid;
diff --git a/security/keys/key.c b/security/keys/key.c
index a6ca39ed3b0..f76c8a546fd 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -218,7 +218,7 @@ serial_exists:
* instantiate the key or discard it before returning
*/
struct key *key_alloc(struct key_type *type, const char *desc,
- uid_t uid, gid_t gid, struct task_struct *ctx,
+ uid_t uid, gid_t gid, const struct cred *cred,
key_perm_t perm, unsigned long flags)
{
struct key_user *user = NULL;
@@ -294,7 +294,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
#endif
/* let the security module know about the key */
- ret = security_key_alloc(key, ctx, flags);
+ ret = security_key_alloc(key, cred, flags);
if (ret < 0)
goto security_error;
@@ -391,7 +391,7 @@ static int __key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
int ret, awaken;
@@ -421,8 +421,8 @@ static int __key_instantiate_and_link(struct key *key,
ret = __key_link(keyring, key);
/* disable the authorisation key */
- if (instkey)
- key_revoke(instkey);
+ if (authkey)
+ key_revoke(authkey);
}
}
@@ -444,14 +444,14 @@ int key_instantiate_and_link(struct key *key,
const void *data,
size_t datalen,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
int ret;
if (keyring)
down_write(&keyring->sem);
- ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey);
+ ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey);
if (keyring)
up_write(&keyring->sem);
@@ -469,7 +469,7 @@ EXPORT_SYMBOL(key_instantiate_and_link);
int key_negate_and_link(struct key *key,
unsigned timeout,
struct key *keyring,
- struct key *instkey)
+ struct key *authkey)
{
struct timespec now;
int ret, awaken;
@@ -504,8 +504,8 @@ int key_negate_and_link(struct key *key,
ret = __key_link(keyring, key);
/* disable the authorisation key */
- if (instkey)
- key_revoke(instkey);
+ if (authkey)
+ key_revoke(authkey);
}
mutex_unlock(&key_construction_mutex);
@@ -743,6 +743,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
key_perm_t perm,
unsigned long flags)
{
+ const struct cred *cred = current_cred();
struct key_type *ktype;
struct key *keyring, *key = NULL;
key_ref_t key_ref;
@@ -802,8 +803,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
}
/* allocate a new key */
- key = key_alloc(ktype, description, current_fsuid(), current_fsgid(),
- current, perm, flags);
+ key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred,
+ perm, flags);
if (IS_ERR(key)) {
key_ref = ERR_CAST(key);
goto error_3;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 8833b447ade..7c72baa02f2 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -866,6 +866,23 @@ static long get_instantiation_keyring(key_serial_t ringid,
return -ENOKEY;
}
+/*
+ * change the request_key authorisation key on the current process
+ */
+static int keyctl_change_reqkey_auth(struct key *key)
+{
+ struct cred *new;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ key_put(new->request_key_auth);
+ new->request_key_auth = key_get(key);
+
+ return commit_creds(new);
+}
+
/*****************************************************************************/
/*
* instantiate the key with the specified payload, and, if one is given, link
@@ -876,12 +893,15 @@ long keyctl_instantiate_key(key_serial_t id,
size_t plen,
key_serial_t ringid)
{
+ const struct cred *cred = current_cred();
struct request_key_auth *rka;
struct key *instkey, *dest_keyring;
void *payload;
long ret;
bool vm = false;
+ kenter("%d,,%zu,%d", id, plen, ringid);
+
ret = -EINVAL;
if (plen > 1024 * 1024 - 1)
goto error;
@@ -889,7 +909,7 @@ long keyctl_instantiate_key(key_serial_t id,
/* the appropriate instantiation authorisation key must have been
* assumed before calling this */
ret = -EPERM;
- instkey = current->cred->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
@@ -931,10 +951,8 @@ long keyctl_instantiate_key(key_serial_t id,
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error2:
if (!vm)
@@ -953,14 +971,17 @@ error:
*/
long keyctl_negate_key(key_serial_t id, unsigned timeout, 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);
+
/* the appropriate instantiation authorisation key must have been
* assumed before calling this */
ret = -EPERM;
- instkey = current->cred->request_key_auth;
+ instkey = cred->request_key_auth;
if (!instkey)
goto error;
@@ -982,10 +1003,8 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
/* discard the assumed authority if it's just been disabled by
* instantiation of the key */
- if (ret == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- }
+ if (ret == 0)
+ keyctl_change_reqkey_auth(NULL);
error:
return ret;
@@ -999,36 +1018,56 @@ error:
*/
long keyctl_set_reqkey_keyring(int reqkey_defl)
{
- struct cred *cred = current->cred;
- int ret;
+ struct cred *new;
+ int ret, old_setting;
+
+ old_setting = current_cred_xxx(jit_keyring);
+
+ if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
+ return old_setting;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
switch (reqkey_defl) {
case KEY_REQKEY_DEFL_THREAD_KEYRING:
- ret = install_thread_keyring();
+ ret = install_thread_keyring_to_cred(new);
if (ret < 0)
- return ret;
+ goto error;
goto set;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- ret = install_process_keyring();
- if (ret < 0)
- return ret;
+ ret = install_process_keyring_to_cred(new);
+ if (ret < 0) {
+ if (ret != -EEXIST)
+ goto error;
+ ret = 0;
+ }
+ goto set;
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_SESSION_KEYRING:
case KEY_REQKEY_DEFL_USER_KEYRING:
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
- set:
- cred->jit_keyring = reqkey_defl;
+ case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+ goto set;
case KEY_REQKEY_DEFL_NO_CHANGE:
- return cred->jit_keyring;
-
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto error;
}
+set:
+ new->jit_keyring = reqkey_defl;
+ commit_creds(new);
+ return old_setting;
+error:
+ abort_creds(new);
+ return -EINVAL;
+
} /* end keyctl_set_reqkey_keyring() */
/*****************************************************************************/
@@ -1087,9 +1126,7 @@ long keyctl_assume_authority(key_serial_t id)
/* we divest ourselves of authority if given an ID of 0 */
if (id == 0) {
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = NULL;
- ret = 0;
+ ret = keyctl_change_reqkey_auth(NULL);
goto error;
}
@@ -1104,10 +1141,12 @@ long keyctl_assume_authority(key_serial_t id)
goto error;
}
- key_put(current->cred->request_key_auth);
- current->cred->request_key_auth = authkey;
- ret = authkey->serial;
+ ret = keyctl_change_reqkey_auth(authkey);
+ if (ret < 0)
+ goto error;
+ key_put(authkey);
+ ret = authkey->serial;
error:
return ret;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index fdf75f90199..ed851574d07 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -245,14 +245,14 @@ static long keyring_read(const struct key *keyring,
* allocate a keyring and link into the destination keyring
*/
struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
- struct task_struct *ctx, unsigned long flags,
+ const struct cred *cred, unsigned long flags,
struct key *dest)
{
struct key *keyring;
int ret;
keyring = key_alloc(&key_type_keyring, description,
- uid, gid, ctx,
+ uid, gid, cred,
(KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
flags);
@@ -281,7 +281,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
* - we propagate the possession attribute from the keyring ref to the key ref
*/
key_ref_t keyring_search_aux(key_ref_t keyring_ref,
- struct task_struct *context,
+ const struct cred *cred,
struct key_type *type,
const void *description,
key_match_func_t match)
@@ -304,7 +304,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
key_check(keyring);
/* top keyring must have search permission to begin the search */
- err = key_task_permission(keyring_ref, context, KEY_SEARCH);
+ err = key_task_permission(keyring_ref, cred, KEY_SEARCH);
if (err < 0) {
key_ref = ERR_PTR(err);
goto error;
@@ -377,7 +377,7 @@ descend:
/* key must have search permissions */
if (key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH) < 0)
+ cred, KEY_SEARCH) < 0)
continue;
/* we set a different error code if we pass a negative key */
@@ -404,7 +404,7 @@ ascend:
continue;
if (key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH) < 0)
+ cred, KEY_SEARCH) < 0)
continue;
/* stack the current position */
@@ -459,7 +459,7 @@ key_ref_t keyring_search(key_ref_t keyring,
if (!type->match)
return ERR_PTR(-ENOKEY);
- return keyring_search_aux(keyring, current,
+ return keyring_search_aux(keyring, current->cred,
type, description, type->match);
} /* end keyring_search() */
diff --git a/security/keys/permission.c b/security/keys/permission.c
index 13c36164f28..5d9fc7b93f2 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -14,24 +14,27 @@
#include "internal.h"
/*****************************************************************************/
-/*
- * check to see whether permission is granted to use a key in the desired way,
- * but permit the security modules to override
+/**
+ * key_task_permission - Check a key can be used
+ * @key_ref: The key to check
+ * @cred: The credentials to use
+ * @perm: The permissions to check for
+ *
+ * Check to see whether permission is granted to use a key in the desired way,
+ * but permit the security modules to override.
+ *
+ * The caller must hold either a ref on cred or must hold the RCU readlock or a
+ * spinlock.
*/
-int key_task_permission(const key_ref_t key_ref,
- struct task_struct *context,
+int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
key_perm_t perm)
{
- const struct cred *cred;
struct key *key;
key_perm_t kperm;
int ret;
key = key_ref_to_ptr(key_ref);
- rcu_read_lock();
- cred = __task_cred(context);
-
/* use the second 8-bits of permissions for keys the caller owns */
if (key->uid == cred->fsuid) {
kperm = key->perm >> 16;
@@ -57,7 +60,6 @@ int key_task_permission(const key_ref_t key_ref,
kperm = key->perm;
use_these_perms:
- rcu_read_lock();
/* use the top 8-bits of permissions for keys the caller possesses
* - possessor permissions are additive with other permissions
@@ -71,7 +73,7 @@ use_these_perms:
return -EACCES;
/* let LSM be the final arbiter */
- return security_key_permission(key_ref, context, perm);
+ return security_key_permission(key_ref, cred, perm);
} /* end key_task_permission() */
diff --git a/security/keys/proc.c b/security/keys/proc.c
index f619170da76..7f508def50e 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -136,8 +136,12 @@ static int proc_keys_show(struct seq_file *m, void *v)
int rc;
/* check whether the current task is allowed to view the key (assuming
- * non-possession) */
- rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW);
+ * non-possession)
+ * - the caller holds a spinlock, and thus the RCU read lock, making our
+ * access to __current_cred() safe
+ */
+ rc = key_task_permission(make_key_ref(key, 0), current_cred(),
+ KEY_VIEW);
if (rc < 0)
return 0;
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 70ee93406f3..df329f684a6 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -42,11 +42,15 @@ struct key_user root_key_user = {
*/
int install_user_keyrings(void)
{
- struct user_struct *user = current->cred->user;
+ struct user_struct *user;
+ const struct cred *cred;
struct key *uid_keyring, *session_keyring;
char buf[20];
int ret;
+ cred = current_cred();
+ user = cred->user;
+
kenter("%p{%u}", user, user->uid);
if (user->uid_keyring) {
@@ -67,7 +71,7 @@ int install_user_keyrings(void)
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
+ cred, KEY_ALLOC_IN_QUOTA,
NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
@@ -83,8 +87,7 @@ int install_user_keyrings(void)
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
- NULL);
+ cred, KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error_release;
@@ -116,142 +119,128 @@ error:
return ret;
}
-/*****************************************************************************/
/*
- * deal with the UID changing
+ * install a fresh thread keyring directly to new credentials
*/
-void switch_uid_keyring(struct user_struct *new_user)
+int install_thread_keyring_to_cred(struct cred *new)
{
-#if 0 /* do nothing for now */
- struct key *old;
-
- /* switch to the new user's session keyring if we were running under
- * root's default session keyring */
- if (new_user->uid != 0 &&
- current->session_keyring == &root_session_keyring
- ) {
- atomic_inc(&new_user->session_keyring->usage);
-
- task_lock(current);
- old = current->session_keyring;
- current->session_keyring = new_user->session_keyring;
- task_unlock(current);
+ struct key *keyring;
- key_put(old);
- }
-#endif
+ keyring = keyring_alloc("_tid", new->uid, new->gid, new,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
-} /* end switch_uid_keyring() */
+ new->thread_keyring = keyring;
+ return 0;
+}
-/*****************************************************************************/
/*
* install a fresh thread keyring, discarding the old one
*/
-int install_thread_keyring(void)
+static int install_thread_keyring(void)
{
- struct task_struct *tsk = current;
- struct key *keyring, *old;
- char buf[20];
+ struct cred *new;
int ret;
- sprintf(buf, "_tid.%u", tsk->pid);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
+ BUG_ON(new->thread_keyring);
+
+ ret = install_thread_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
}
- task_lock(tsk);
- old = tsk->cred->thread_keyring;
- tsk->cred->thread_keyring = keyring;
- task_unlock(tsk);
+ return commit_creds(new);
+}
- ret = 0;
+/*
+ * install a process keyring directly to a credentials struct
+ * - returns -EEXIST if there was already a process keyring, 0 if one installed,
+ * and other -ve on any other error
+ */
+int install_process_keyring_to_cred(struct cred *new)
+{
+ struct key *keyring;
+ int ret;
- key_put(old);
-error:
+ if (new->tgcred->process_keyring)
+ return -EEXIST;
+
+ keyring = keyring_alloc("_pid", new->uid, new->gid,
+ new, 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;
+}
-} /* end install_thread_keyring() */
-
-/*****************************************************************************/
/*
* make sure a process keyring is installed
+ * - we
*/
-int install_process_keyring(void)
+static int install_process_keyring(void)
{
- struct task_struct *tsk = current;
- struct key *keyring;
- char buf[20];
+ struct cred *new;
int ret;
- might_sleep();
-
- if (!tsk->cred->tgcred->process_keyring) {
- sprintf(buf, "_pid.%u", tsk->tgid);
-
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
-
- /* attach keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- if (!tsk->cred->tgcred->process_keyring) {
- tsk->cred->tgcred->process_keyring = keyring;
- keyring = NULL;
- }
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- key_put(keyring);
+ ret = install_process_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret != -EEXIST ?: 0;
}
- ret = 0;
-error:
- return ret;
-
-} /* end install_process_keyring() */
+ return commit_creds(new);
+}
-/*****************************************************************************/
/*
- * install a session keyring, discarding the old one
- * - if a keyring is not supplied, an empty one is invented
+ * install a session keyring directly to a credentials struct
*/
-static int install_session_keyring(struct key *keyring)
+static int install_session_keyring_to_cred(struct cred *cred,
+ struct key *keyring)
{
- struct task_struct *tsk = current;
unsigned long flags;
struct key *old;
- char buf[20];
might_sleep();
/* create an empty session keyring */
if (!keyring) {
- sprintf(buf, "_ses.%u", tsk->tgid);
-
flags = KEY_ALLOC_QUOTA_OVERRUN;
- if (tsk->cred->tgcred->session_keyring)
+ if (cred->tgcred->session_keyring)
flags = KEY_ALLOC_IN_QUOTA;
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid,
- tsk, flags, NULL);
+ keyring = keyring_alloc("_ses", cred->uid, cred->gid,
+ cred, flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
- }
- else {
+ } else {
atomic_inc(&keyring->usage);
}
/* install the keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->session_keyring;
- rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring);
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ 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 */
@@ -261,38 +250,29 @@ static int install_session_keyring(struct key *keyring)
}
return 0;
+}
-} /* end install_session_keyring() */
-
-/*****************************************************************************/
/*
- * copy the keys for fork
+ * install a session keyring, discarding the old one
+ * - if a keyring is not supplied, an empty one is invented
*/
-int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
+static int install_session_keyring(struct key *keyring)
{
- key_check(tsk->cred->thread_keyring);
- key_check(tsk->cred->request_key_auth);
-
- /* no thread keyring yet */
- tsk->cred->thread_keyring = NULL;
-
- /* copy the request_key() authorisation for this thread */
- key_get(tsk->cred->request_key_auth);
-
- return 0;
+ struct cred *new;
+ int ret;
-} /* end copy_keys() */
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
-/*****************************************************************************/
-/*
- * dispose of per-thread keys upon thread exit
- */
-void exit_keys(struct task_struct *tsk)
-{
- key_put(tsk->cred->thread_keyring);
- key_put(tsk->cred->request_key_auth);
+ ret = install_session_keyring_to_cred(new, NULL);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
+ }
-} /* end exit_keys() */
+ return commit_creds(new);
+}
/*****************************************************************************/
/*
@@ -300,38 +280,41 @@ void exit_keys(struct task_struct *tsk)
*/
int exec_keys(struct task_struct *tsk)
{
- struct key *old;
+ struct thread_group_cred *tgcred = NULL;
+ struct cred *new;
- /* newly exec'd tasks don't get a thread keyring */
- task_lock(tsk);
- old = tsk->cred->thread_keyring;
- tsk->cred->thread_keyring = NULL;
- task_unlock(tsk);
+#ifdef CONFIG_KEYS
+ tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL);
+ if (!tgcred)
+ return -ENOMEM;
+#endif
- key_put(old);
+ new = prepare_creds();
+ if (new < 0)
+ return -ENOMEM;
- /* discard the process keyring from a newly exec'd task */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->process_keyring;
- tsk->cred->tgcred->process_keyring = NULL;
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ /* newly exec'd tasks don't get a thread keyring */
+ key_put(new->thread_keyring);
+ new->thread_keyring = NULL;
- key_put(old);
+ /* create a new per-thread-group creds for all this set of threads to
+ * share */
+ memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred));
- return 0;
+ atomic_set(&tgcred->usage, 1);
+ spin_lock_init(&tgcred->lock);
-} /* end exec_keys() */
+ /* inherit the session keyring; new process keyring */
+ key_get(tgcred->session_keyring);
+ tgcred->process_keyring = NULL;
-/*****************************************************************************/
-/*
- * deal with SUID programs
- * - we might want to make this invent a new session keyring
- */
-int suid_keys(struct task_struct *tsk)
-{
+ release_tgcred(new);
+ new->tgcred = tgcred;
+
+ commit_creds(new);
return 0;
-} /* end suid_keys() */
+} /* end exec_keys() */
/*****************************************************************************/
/*
@@ -376,16 +359,13 @@ void key_fsgid_changed(struct task_struct *tsk)
key_ref_t search_process_keyrings(struct key_type *type,
const void *description,
key_match_func_t match,
- struct task_struct *context)
+ const struct cred *cred)
{
struct request_key_auth *rka;
- struct cred *cred;
key_ref_t key_ref, ret, err;
might_sleep();
- cred = get_task_cred(context);
-
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
* otherwise we want to return a sample error (probably -EACCES) if
@@ -401,7 +381,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
if (cred->thread_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->thread_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -422,7 +402,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
if (cred->tgcred->process_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->tgcred->process_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -446,7 +426,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
make_key_ref(rcu_dereference(
cred->tgcred->session_keyring),
1),
- context, type, description, match);
+ cred, type, description, match);
rcu_read_unlock();
if (!IS_ERR(key_ref))
@@ -468,7 +448,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
else if (cred->user->session_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->user->session_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -490,7 +470,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
* - we don't permit access to request_key auth keys via this method
*/
if (cred->request_key_auth &&
- context == current &&
+ cred == current_cred() &&
type != &key_type_request_key_auth
) {
/* defend against the auth key being revoked */
@@ -500,7 +480,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
rka = cred->request_key_auth->payload.data;
key_ref = search_process_keyrings(type, description,
- match, rka->context);
+ match, rka->cred);
up_read(&cred->request_key_auth->sem);
@@ -527,7 +507,6 @@ key_ref_t search_process_keyrings(struct key_type *type,
key_ref = ret ? ret : err;
found:
- put_cred(cred);
return key_ref;
} /* end search_process_keyrings() */
@@ -552,8 +531,7 @@ key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
key_perm_t perm)
{
struct request_key_auth *rka;
- struct task_struct *t = current;
- struct cred *cred;
+ const struct cred *cred;
struct key *key;
key_ref_t key_ref, skey_ref;
int ret;
@@ -608,6 +586,7 @@ try_again:
goto error;
ret = install_session_keyring(
cred->user->session_keyring);
+
if (ret < 0)
goto error;
goto reget_creds;
@@ -693,7 +672,7 @@ try_again:
/* check to see if we possess the key */
skey_ref = search_process_keyrings(key->type, key,
lookup_user_key_possessed,
- current);
+ cred);
if (!IS_ERR(skey_ref)) {
key_put(key);
@@ -725,7 +704,7 @@ try_again:
goto invalid_key;
/* check the permissions */
- ret = key_task_permission(key_ref, t, perm);
+ ret = key_task_permission(key_ref, cred, perm);
if (ret < 0)
goto invalid_key;
@@ -755,21 +734,33 @@ reget_creds:
*/
long join_session_keyring(const char *name)
{
- struct task_struct *tsk = current;
- struct cred *cred = current->cred;
+ const struct cred *old;
+ struct cred *new;
struct key *keyring;
- long ret;
+ 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 (!is_single_threaded(current))
+ return -EMLINK;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ old = current_cred();
/* if no name is provided, install an anonymous keyring */
if (!name) {
- ret = install_session_keyring(NULL);
+ ret = install_session_keyring_to_cred(new, NULL);
if (ret < 0)
goto error;
- rcu_read_lock();
- ret = rcu_dereference(cred->tgcred->session_keyring)->serial;
- rcu_read_unlock();
- goto error;
+ serial = new->tgcred->session_keyring->serial;
+ ret = commit_creds(new);
+ if (ret == 0)
+ ret = serial;
+ goto okay;
}
/* allow the user to join or create a named keyring */
@@ -779,29 +770,33 @@ 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, cred->uid, cred->gid, tsk,
+ keyring = keyring_alloc(name, old->uid, old->gid, old,
KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
- }
- else if (IS_ERR(keyring)) {
+ } else if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
/* we've got a keyring - now to install it */
- ret = install_session_keyring(keyring);
+ ret = install_session_keyring_to_cred(new, keyring);
if (ret < 0)
goto error2;
+ commit_creds(new);
+ mutex_unlock(&key_session_mutex);
+
ret = keyring->serial;
key_put(keyring);
+okay:
+ return ret;
error2:
mutex_unlock(&key_session_mutex);
error:
+ abort_creds(new);
return ret;
-
-} /* end join_session_keyring() */
+}
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 3d12558362d..0e04f72ef2d 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -83,8 +83,10 @@ static int call_sbin_request_key(struct key_construction *cons,
/* allocate a new session keyring */