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-rw-r--r--security/keys/internal.h3
-rw-r--r--security/keys/key.c57
-rw-r--r--security/keys/keyctl.c61
-rw-r--r--security/keys/keyring.c25
-rw-r--r--security/keys/proc.c7
-rw-r--r--security/keys/process_keys.c24
-rw-r--r--security/keys/request_key.c36
-rw-r--r--security/keys/request_key_auth.c2
-rw-r--r--security/keys/user_defined.c25
9 files changed, 176 insertions, 64 deletions
diff --git a/security/keys/internal.h b/security/keys/internal.h
index e066e6057955..3c2877f0663e 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -99,7 +99,8 @@ extern int install_process_keyring(struct task_struct *tsk);
extern struct key *request_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
- struct key *dest_keyring);
+ struct key *dest_keyring,
+ unsigned long flags);
/*
* request_key authorisation
diff --git a/security/keys/key.c b/security/keys/key.c
index 51f851557389..80de8c3e9cc3 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -11,15 +11,16 @@
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/poison.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/security.h>
#include <linux/workqueue.h>
+#include <linux/random.h>
#include <linux/err.h>
#include "internal.h"
static kmem_cache_t *key_jar;
-static key_serial_t key_serial_next = 3;
struct rb_root key_serial_tree; /* tree of keys indexed by serial */
DEFINE_SPINLOCK(key_serial_lock);
@@ -169,22 +170,23 @@ static void __init __key_insert_serial(struct key *key)
/*****************************************************************************/
/*
* assign a key the next unique serial number
- * - we work through all the serial numbers between 2 and 2^31-1 in turn and
- * then wrap
+ * - these are assigned randomly to avoid security issues through covert
+ * channel problems
*/
static inline void key_alloc_serial(struct key *key)
{
struct rb_node *parent, **p;
struct key *xkey;
- spin_lock(&key_serial_lock);
-
- /* propose a likely serial number and look for a hole for it in the
+ /* propose a random serial number and look for a hole for it in the
* serial number tree */
- key->serial = key_serial_next;
- if (key->serial < 3)
- key->serial = 3;
- key_serial_next = key->serial + 1;
+ do {
+ get_random_bytes(&key->serial, sizeof(key->serial));
+
+ key->serial >>= 1; /* negative numbers are not permitted */
+ } while (key->serial < 3);
+
+ spin_lock(&key_serial_lock);
parent = NULL;
p = &key_serial_tree.rb_node;
@@ -204,12 +206,11 @@ static inline void key_alloc_serial(struct key *key)
/* we found a key with the proposed serial number - walk the tree from
* that point looking for the next unused serial number */
- serial_exists:
+serial_exists:
for (;;) {
- key->serial = key_serial_next;
+ key->serial++;
if (key->serial < 2)
key->serial = 2;
- key_serial_next = key->serial + 1;
if (!rb_parent(parent))
p = &key_serial_tree.rb_node;
@@ -228,7 +229,7 @@ static inline void key_alloc_serial(struct key *key)
}
/* we've found a suitable hole - arrange for this key to occupy it */
- insert_here:
+insert_here:
rb_link_node(&key->serial_node, parent, p);
rb_insert_color(&key->serial_node, &key_serial_tree);
@@ -248,7 +249,7 @@ static inline void key_alloc_serial(struct key *key)
*/
struct key *key_alloc(struct key_type *type, const char *desc,
uid_t uid, gid_t gid, struct task_struct *ctx,
- key_perm_t perm, int not_in_quota)
+ key_perm_t perm, unsigned long flags)
{
struct key_user *user = NULL;
struct key *key;
@@ -269,12 +270,14 @@ struct key *key_alloc(struct key_type *type, const char *desc,
/* check that the user's quota permits allocation of another key and
* its description */
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
- if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS ||
- user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES
- )
- goto no_quota;
+ if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
+ if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS ||
+ user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES
+ )
+ goto no_quota;
+ }
user->qnkeys++;
user->qnbytes += quotalen;
@@ -308,7 +311,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
key->payload.data = NULL;
key->security = NULL;
- if (!not_in_quota)
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
key->flags |= 1 << KEY_FLAG_IN_QUOTA;
memset(&key->type_data, 0, sizeof(key->type_data));
@@ -318,7 +321,7 @@ 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);
+ ret = security_key_alloc(key, ctx, flags);
if (ret < 0)
goto security_error;
@@ -332,7 +335,7 @@ error:
security_error:
kfree(key->description);
kmem_cache_free(key_jar, key);
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
user->qnkeys--;
user->qnbytes -= quotalen;
@@ -345,7 +348,7 @@ security_error:
no_memory_3:
kmem_cache_free(key_jar, key);
no_memory_2:
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
user->qnkeys--;
user->qnbytes -= quotalen;
@@ -761,7 +764,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
const char *description,
const void *payload,
size_t plen,
- int not_in_quota)
+ unsigned long flags)
{
struct key_type *ktype;
struct key *keyring, *key = NULL;
@@ -822,7 +825,7 @@ 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, not_in_quota);
+ current, perm, flags);
if (IS_ERR(key)) {
key_ref = ERR_PTR(PTR_ERR(key));
goto error_3;
@@ -986,7 +989,7 @@ void unregister_key_type(struct key_type *ktype)
if (key->type == ktype) {
if (ktype->destroy)
ktype->destroy(key);
- memset(&key->payload, 0xbd, sizeof(key->payload));
+ memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
}
}
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index ed71d86d2ce2..329411cf8768 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -102,7 +102,7 @@ asmlinkage long sys_add_key(const char __user *_type,
/* create or update the requested key and add it to the target
* keyring */
key_ref = key_create_or_update(keyring_ref, type, description,
- payload, plen, 0);
+ payload, plen, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key_ref)) {
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
@@ -184,7 +184,8 @@ asmlinkage long sys_request_key(const char __user *_type,
/* do the search */
key = request_key_and_link(ktype, description, callout_info,
- key_ref_to_ptr(dest_ref));
+ key_ref_to_ptr(dest_ref),
+ KEY_ALLOC_IN_QUOTA);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
@@ -672,6 +673,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
*/
long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
{
+ struct key_user *newowner, *zapowner = NULL;
struct key *key;
key_ref_t key_ref;
long ret;
@@ -695,19 +697,50 @@ 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)
- goto no_access;
+ 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))
- goto no_access;
+ goto error_put;
}
- /* change the UID (have to update the quotas) */
+ /* change the UID */
if (uid != (uid_t) -1 && uid != key->uid) {
- /* don't support UID changing yet */
- ret = -EOPNOTSUPP;
- goto no_access;
+ ret = -ENOMEM;
+ 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)) {
+ spin_lock(&newowner->lock);
+ if (newowner->qnkeys + 1 >= KEYQUOTA_MAX_KEYS ||
+ newowner->qnbytes + key->quotalen >=
+ KEYQUOTA_MAX_BYTES)
+ goto quota_overrun;
+
+ newowner->qnkeys++;
+ newowner->qnbytes += key->quotalen;
+ spin_unlock(&newowner->lock);
+
+ spin_lock(&key->user->lock);
+ key->user->qnkeys--;
+ key->user->qnbytes -= key->quotalen;
+ spin_unlock(&key->user->lock);
+ }
+
+ atomic_dec(&key->user->nkeys);
+ atomic_inc(&newowner->nkeys);
+
+ if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
+ atomic_dec(&key->user->nikeys);
+ atomic_inc(&newowner->nikeys);
+ }
+
+ zapowner = key->user;
+ key->user = newowner;
+ key->uid = uid;
}
/* change the GID */
@@ -716,12 +749,20 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
ret = 0;
- no_access:
+error_put:
up_write(&key->sem);
key_put(key);
- error:
+ if (zapowner)
+ key_user_put(zapowner);
+error:
return ret;
+quota_overrun:
+ spin_unlock(&newowner->lock);
+ zapowner = newowner;
+ ret = -EDQUOT;
+ goto error_put;
+
} /* end keyctl_chown_key() */
/*****************************************************************************/
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 1357207fc9df..e8d02acc51e7 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -49,6 +49,7 @@ static inline unsigned keyring_hash(const char *desc)
static int keyring_instantiate(struct key *keyring,
const void *data, size_t datalen);
static int keyring_match(const struct key *keyring, const void *criterion);
+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);
static long keyring_read(const struct key *keyring,
@@ -59,6 +60,7 @@ struct key_type key_type_keyring = {
.def_datalen = sizeof(struct keyring_list),
.instantiate = keyring_instantiate,
.match = keyring_match,
+ .revoke = keyring_revoke,
.destroy = keyring_destroy,
.describe = keyring_describe,
.read = keyring_read,
@@ -240,7 +242,7 @@ 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, int not_in_quota,
+ struct task_struct *ctx, unsigned long flags,
struct key *dest)
{
struct key *keyring;
@@ -249,7 +251,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
keyring = key_alloc(&key_type_keyring, description,
uid, gid, ctx,
(KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
- not_in_quota);
+ flags);
if (!IS_ERR(keyring)) {
ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
@@ -953,3 +955,22 @@ int keyring_clear(struct key *keyring)
} /* end keyring_clear() */
EXPORT_SYMBOL(keyring_clear);
+
+/*****************************************************************************/
+/*
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+static void keyring_revoke(struct key *keyring)
+{
+ struct keyring_list *klist = keyring->payload.subscriptions;
+
+ /* adjust the quota */
+ key_payload_reserve(keyring, 0);
+
+ if (klist) {
+ rcu_assign_pointer(keyring->payload.subscriptions, NULL);
+ call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
+ }
+
+} /* end keyring_revoke() */
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 12b750e51fbf..686a9ee0c5de 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -137,6 +137,13 @@ static int proc_keys_show(struct seq_file *m, void *v)
struct timespec now;
unsigned long timo;
char xbuf[12];
+ 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);
+ if (rc < 0)
+ return 0;
now = current_kernel_time();
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 4d9825f9962c..32150cf7c37f 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -77,7 +77,8 @@ int alloc_uid_keyring(struct user_struct *user,
/* concoct a default session keyring */
sprintf(buf, "_uid_ses.%u", user->uid);
- session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, 0, NULL);
+ session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error;
@@ -87,8 +88,8 @@ int alloc_uid_keyring(struct user_struct *user,
* keyring */
sprintf(buf, "_uid.%u", user->uid);
- uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, 0,
- session_keyring);
+ uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
+ KEY_ALLOC_IN_QUOTA, session_keyring);
if (IS_ERR(uid_keyring)) {
key_put(session_keyring);
ret = PTR_ERR(uid_keyring);
@@ -144,7 +145,8 @@ int install_thread_keyring(struct task_struct *tsk)
sprintf(buf, "_tid.%u", tsk->pid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
@@ -178,7 +180,8 @@ int install_process_keyring(struct task_struct *tsk)
if (!tsk->signal->process_keyring) {
sprintf(buf, "_pid.%u", tsk->tgid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
@@ -209,6 +212,7 @@ error:
static int install_session_keyring(struct task_struct *tsk,
struct key *keyring)
{
+ unsigned long flags;
struct key *old;
char buf[20];
@@ -218,7 +222,12 @@ static int install_session_keyring(struct task_struct *tsk,
if (!keyring) {
sprintf(buf, "_ses.%u", tsk->tgid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ flags = KEY_ALLOC_QUOTA_OVERRUN;
+ if (tsk->signal->session_keyring)
+ flags = KEY_ALLOC_IN_QUOTA;
+
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
}
@@ -728,7 +737,8 @@ long join_session_keyring(const char *name)
keyring = find_keyring_by_name(name, 0);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, 0, NULL);
+ keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index eab66a06ca53..58d1efd4fc2c 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -48,8 +48,8 @@ static int call_sbin_request_key(struct key *key,
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
- keyring = keyring_alloc(desc, current->fsuid, current->fsgid,
- current, 1, NULL);
+ keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error_alloc;
@@ -126,7 +126,8 @@ error_alloc:
*/
static struct key *__request_key_construction(struct key_type *type,
const char *description,
- const char *callout_info)
+ const char *callout_info,
+ unsigned long flags)
{
request_key_actor_t actor;
struct key_construction cons;
@@ -134,12 +135,12 @@ static struct key *__request_key_construction(struct key_type *type,
struct key *key, *authkey;
int ret, negated;
- kenter("%s,%s,%s", type->name, description, callout_info);
+ kenter("%s,%s,%s,%lx", type->name, description, callout_info, flags);
/* create a key and add it to the queue */
key = key_alloc(type, description,
- current->fsuid, current->fsgid,
- current, KEY_POS_ALL, 0);
+ current->fsuid, current->fsgid, current, KEY_POS_ALL,
+ flags);
if (IS_ERR(key))
goto alloc_failed;
@@ -258,15 +259,16 @@ alloc_failed:
static struct key *request_key_construction(struct key_type *type,
const char *description,
struct key_user *user,
- const char *callout_info)
+ const char *callout_info,
+ unsigned long flags)
{
struct key_construction *pcons;
struct key *key, *ckey;
DECLARE_WAITQUEUE(myself, current);
- kenter("%s,%s,{%d},%s",
- type->name, description, user->uid, callout_info);
+ kenter("%s,%s,{%d},%s,%lx",
+ type->name, description, user->uid, callout_info, flags);
/* see if there's such a key under construction already */
down_write(&key_construction_sem);
@@ -282,7 +284,8 @@ static struct key *request_key_construction(struct key_type *type,
}
/* see about getting userspace to construct the key */
- key = __request_key_construction(type, description, callout_info);
+ key = __request_key_construction(type, description, callout_info,
+ flags);
error:
kleave(" = %p", key);
return key;
@@ -389,14 +392,15 @@ static void request_key_link(struct key *key, struct key *dest_keyring)
struct key *request_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
- struct key *dest_keyring)
+ struct key *dest_keyring,
+ unsigned long flags)
{
struct key_user *user;
struct key *key;
key_ref_t key_ref;
- kenter("%s,%s,%s,%p",
- type->name, description, callout_info, dest_keyring);
+ kenter("%s,%s,%s,%p,%lx",
+ type->name, description, callout_info, dest_keyring, flags);
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match,
@@ -429,7 +433,8 @@ struct key *request_key_and_link(struct key_type *type,
/* ask userspace (returns NULL if it waited on a key
* being constructed) */
key = request_key_construction(type, description,
- user, callout_info);
+ user, callout_info,
+ flags);
if (key)
break;
@@ -485,7 +490,8 @@ struct key *request_key(struct key_type *type,
const char *description,
const char *callout_info)
{
- return request_key_and_link(type, description, callout_info, NULL);
+ return request_key_and_link(type, description, callout_info, NULL,
+ KEY_ALLOC_IN_QUOTA);
} /* end request_key() */
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index cb9817ced3fd..cbf58a91b00a 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -187,7 +187,7 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info)
authkey = key_alloc(&key_type_request_key_auth, desc,
current->fsuid, current->fsgid, current,
KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
- KEY_USR_VIEW, 1);
+ KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(authkey)) {
ret = PTR_ERR(authkey);
goto error_alloc;
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 8e71895b97a7..5bbfdebb7acf 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -28,6 +28,7 @@ struct key_type key_type_user = {
.instantiate = user_instantiate,
.update = user_update,
.match = user_match,
+ .revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
@@ -67,6 +68,7 @@ error:
return ret;
} /* end user_instantiate() */
+
EXPORT_SYMBOL_GPL(user_instantiate);
/*****************************************************************************/
@@ -141,7 +143,28 @@ EXPORT_SYMBOL_GPL(user_match);
/*****************************************************************************/
/*
- * dispose of the data dangling from the corpse of a user
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+void user_revoke(struct key *key)
+{
+ struct user_key_payload *upayload = key->payload.data;
+
+ /* clear the quota */
+ key_payload_reserve(key, 0);
+
+ if (upayload) {
+ rcu_assign_pointer(key->payload.data, NULL);
+ call_rcu(&upayload->rcu, user_update_rcu_disposal);
+ }
+
+} /* end user_revoke() */
+
+EXPORT_SYMBOL(user_revoke);
+
+/*****************************************************************************/
+/*
+ * dispose of the data dangling from the corpse of a user key
*/
void user_destroy(struct key *key)
{
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