diff options
Diffstat (limited to 'security/keys')
| -rw-r--r-- | security/keys/Kconfig | 71 | ||||
| -rw-r--r-- | security/keys/Makefile | 12 | ||||
| -rw-r--r-- | security/keys/compat.c | 3 | ||||
| -rw-r--r-- | security/keys/gc.c | 94 | ||||
| -rw-r--r-- | security/keys/internal.h | 15 | ||||
| -rw-r--r-- | security/keys/key.c | 25 | ||||
| -rw-r--r-- | security/keys/keyctl.c | 34 | ||||
| -rw-r--r-- | security/keys/keyring.c | 167 | ||||
| -rw-r--r-- | security/keys/permission.c | 43 | ||||
| -rw-r--r-- | security/keys/proc.c | 3 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 2 |
11 files changed, 345 insertions, 124 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig new file mode 100644 index 00000000000..a90d6d300db --- /dev/null +++ b/security/keys/Kconfig @@ -0,0 +1,71 @@ +# +# Key management configuration +# + +config KEYS + bool "Enable access key retention support" + 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 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 a56f1ffdc64..504aaa00838 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 +15,12 @@ obj-y := \ request_key.o \ request_key_auth.o \ user_defined.o - -obj-$(CONFIG_TRUSTED_KEYS) += trusted.o -obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_SYSCTL) += sysctl.o + +# +# Key types +# +obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ diff --git a/security/keys/compat.c b/security/keys/compat.c index 4c48e13448f..fab4f8dda6c 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -135,6 +135,9 @@ asmlinkage long compat_sys_keyctl(u32 option, return compat_keyctl_instantiate_key_iov( arg2, compat_ptr(arg3), arg4, arg5); + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key(arg2); + default: return -EOPNOTSUPP; } diff --git a/security/keys/gc.c b/security/keys/gc.c index a42b45531aa..61ab7c82ebb 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -72,6 +72,15 @@ void key_schedule_gc(time_t gc_at) } /* + * Schedule a dead links collection run. + */ +void key_schedule_gc_links(void) +{ + set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags); + queue_work(system_nrt_wq, &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. */ @@ -79,8 +88,7 @@ static void key_gc_timer_func(unsigned long data) { kenter(""); key_gc_next_run = LONG_MAX; - set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags); - queue_work(system_nrt_wq, &key_gc_work); + key_schedule_gc_links(); } /* @@ -131,12 +139,12 @@ void key_gc_keytype(struct key_type *ktype) static void key_gc_keyring(struct key *keyring, time_t limit) { struct keyring_list *klist; - struct key *key; int loop; kenter("%x", key_serial(keyring)); - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) goto dont_gc; /* scan the keyring looking for dead keys */ @@ -148,9 +156,8 @@ static void key_gc_keyring(struct key *keyring, time_t limit) loop = klist->nkeys; smp_rmb(); for (loop--; loop >= 0; loop--) { - key = klist->keys[loop]; - if (test_bit(KEY_FLAG_DEAD, &key->flags) || - (key->expiry > 0 && key->expiry <= limit)) + struct key *key = rcu_dereference(klist->keys[loop]); + if (key_is_dead(key, limit)) goto do_gc; } @@ -168,38 +175,45 @@ do_gc: } /* - * Garbage collect an unreferenced, detached key + * Garbage collect a list of unreferenced, detached keys */ -static noinline void key_gc_unused_key(struct key *key) +static noinline void key_gc_unused_keys(struct list_head *keys) { - 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); - } + while (!list_empty(keys)) { + struct key *key = + list_entry(keys->next, struct key, graveyard_link); + list_del(&key->graveyard_link); + + 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); + atomic_dec(&key->user->nkeys); + if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + atomic_dec(&key->user->nikeys); - key_user_put(key->user); + key_user_put(key->user); - /* now throw away the key memory */ - if (key->type->destroy) - key->type->destroy(key); + /* now throw away the key memory */ + if (key->type->destroy) + key->type->destroy(key); - kfree(key->description); + kfree(key->description); #ifdef KEY_DEBUGGING - key->magic = KEY_DEBUG_MAGIC_X; + key->magic = KEY_DEBUG_MAGIC_X; #endif - kmem_cache_free(key_jar, key); + kmem_cache_free(key_jar, key); + } } /* @@ -211,6 +225,7 @@ static noinline void key_gc_unused_key(struct key *key) */ static void key_garbage_collector(struct work_struct *work) { + 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 */ @@ -316,15 +331,22 @@ maybe_resched: key_schedule_gc(new_timer); } - if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) { - /* Make sure everyone revalidates their keys if we marked a - * bunch as being dead and make sure all keyring ex-payloads - * are destroyed. + 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("dead sync"); + 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)) { @@ -359,7 +381,7 @@ found_unreferenced_key: rb_erase(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); - key_gc_unused_key(key); + list_add_tail(&key->graveyard_link, &graveyard); gc_state |= KEY_GC_REAP_AGAIN; goto maybe_resched; diff --git a/security/keys/internal.h b/security/keys/internal.h index 65647f82558..f711b094ed4 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -152,7 +152,8 @@ extern long join_session_keyring(const char *name); 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, @@ -197,6 +198,17 @@ 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(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); @@ -225,6 +237,7 @@ 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 __user *, diff --git a/security/keys/key.c b/security/keys/key.c index 7e6034793af..50d96d4e06f 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -955,6 +955,28 @@ 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. * @@ -980,6 +1002,8 @@ 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: @@ -1002,6 +1026,7 @@ void unregister_key_type(struct key_type *ktype) list_del_init(&ktype->link); 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); diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index fb767c6cd99..ddb3e05bc5f 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -375,6 +375,37 @@ 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_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. * @@ -1622,6 +1653,9 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, (unsigned) arg4, (key_serial_t) arg5); + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key((key_serial_t) arg2); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index d605f75292e..7445875f681 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -25,6 +25,15 @@ (keyring)->payload.subscriptions, \ rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) +#define rcu_deref_link_locked(klist, index, keyring) \ + (rcu_dereference_protected( \ + (klist)->keys[index], \ + rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) + +#define MAX_KEYRING_LINKS \ + min_t(size_t, USHRT_MAX - 1, \ + ((PAGE_SIZE - sizeof(struct keyring_list)) / sizeof(struct key *))) + #define KEY_LINK_FIXQUOTA 1UL /* @@ -138,6 +147,11 @@ static int keyring_match(const struct key *keyring, const void *description) /* * 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) { @@ -154,11 +168,10 @@ static void keyring_destroy(struct key *keyring) write_unlock(&keyring_name_lock); } - klist = rcu_dereference_check(keyring->payload.subscriptions, - atomic_read(&keyring->usage) == 0); + klist = rcu_access_pointer(keyring->payload.subscriptions); if (klist) { for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); + key_put(rcu_access_pointer(klist->keys[loop])); kfree(klist); } } @@ -214,7 +227,8 @@ static long keyring_read(const struct key *keyring, ret = -EFAULT; for (loop = 0; loop < klist->nkeys; loop++) { - key = klist->keys[loop]; + key = rcu_deref_link_locked(klist, loop, + keyring); tmp = sizeof(key_serial_t); if (tmp > buflen) @@ -309,6 +323,8 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, bool no_state_check) { struct { + /* Need a separate keylist pointer for RCU purposes */ + struct key *keyring; struct keyring_list *keylist; int kix; } stack[KEYRING_SEARCH_MAX_DEPTH]; @@ -366,13 +382,17 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, /* 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)) || + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_NEGATIVE)) || (keyring->expiry && now.tv_sec >= keyring->expiry)) goto error_2; /* start processing a new keyring */ descend: - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) + kflags = keyring->flags; + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) goto not_this_keyring; keylist = rcu_dereference(keyring->payload.subscriptions); @@ -383,16 +403,17 @@ descend: nkeys = keylist->nkeys; smp_rmb(); for (kix = 0; kix < nkeys; kix++) { - key = keylist->keys[kix]; + key = rcu_dereference(keylist->keys[kix]); kflags = key->flags; /* ignore keys not of this type */ if (key->type != type) continue; - /* skip revoked keys and expired keys */ + /* skip invalidated, revoked and expired keys */ if (!no_state_check) { - if (kflags & (1 << KEY_FLAG_REVOKED)) + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) continue; if (key->expiry && now.tv_sec >= key->expiry) @@ -426,7 +447,7 @@ ascend: nkeys = keylist->nkeys; smp_rmb(); for (; kix < nkeys; kix++) { - key = keylist->keys[kix]; + key = rcu_dereference(keylist->keys[kix]); if (key->type != &key_type_keyring) continue; @@ -441,6 +462,7 @@ ascend: continue; /* stack the current position */ + stack[sp].keyring = keyring; stack[sp].keylist = keylist; stack[sp].kix = kix; sp++; @@ -456,6 +478,7 @@ not_this_keyring: if (sp > 0) { /* resume the processing of a keyring higher up in the tree */ sp--; + keyring = stack[sp].keyring; keylist = stack[sp].keylist; kix = stack[sp].kix + 1; goto ascend; @@ -467,6 +490,10 @@ not_this_keyring: /* we found a viable match */ found: atomic_inc(&key->usage); + key->last_used_at = now.tv_sec; + keyring->last_used_at = now.tv_sec; + while (sp > 0) + stack[--sp].keyring->last_used_at = now.tv_sec; key_check(key); key_ref = make_key_ref(key, possessed); error_2: @@ -531,14 +558,14 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref, nkeys = klist->nkeys; smp_rmb(); for (loop = 0; loop < nkeys ; loop++) { - key = klist->keys[loop]; - + key = rcu_dereference(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) + !(key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) ) goto found; } @@ -549,6 +576,8 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref, found: atomic_inc(&key->usage); + keyring->last_used_at = key->last_used_at = + current_kernel_time().tv_sec; rcu_read_unlock(); return make_key_ref(key, possessed); } @@ -602,6 +631,7 @@ 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; } } @@ -654,7 +684,7 @@ ascend: nkeys = keylist->nkeys; smp_rmb(); for (; kix < nkeys; kix++) { - key = keylist->keys[kix]; + key = rcu_dereference(keylist->keys[kix]); if (key == A) goto cycle_detected; @@ -711,7 +741,7 @@ static void keyring_unlink_rcu_disposal(struct rcu_head *rcu) container_of(rcu, struct keyring_list, rcu); if (klist->delkey != USHRT_MAX) - key_put(klist->keys[klist->delkey]); + key_put(rcu_access_pointer(klist->keys[klist->delkey])); kfree(klist); } @@ -725,8 +755,9 @@ int __key_link_begin(struct key *keyring, const struct key_type *type, struct keyring_list *klist, *nklist; unsigned long prealloc; unsigned max; + time_t lowest_lru; size_t size; - int loop, ret; + int loop, lru, ret; kenter("%d,%s,%s,", key_serial(keyring), type->name, description); @@ -747,31 +778,39 @@ int __key_link_begin(struct key *keyring, const struct key_type *type, klist = rcu_dereference_locked_keyring(keyring); /* see if there's a matching key we can displace */ + lru = -1; if (klist && klist->nkeys > 0) { + lowest_lru = TIME_T_MAX; 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; + struct key *key = rcu_deref_link_locked(klist, loop, + keyring); + if (key->type == type && + strcmp(key->description, description) == 0) { + /* Found a match - we'll replace the link with + * one to the new key. We record the slot + * position. + */ + klist->delkey = loop; + prealloc = 0; goto done; } + if (key->last_used_at < lowest_lru) { + lowest_lru = key->last_used_at; + lru = loop; + } } } + /* If the keyring is full then do an LRU discard */ + if (klist && + klist->nkeys == klist->maxkeys && + klist->maxkeys >= MAX_KEYRING_LINKS) { + kdebug("LRU discard %d\n", lru); + klist->delkey = lru; + prealloc = 0; + goto done; + } + /* check that we aren't going to overrun the user's quota */ ret = key_payload_reserve(keyring, keyring->datalen + KEYQUOTA_LINK_BYTES); @@ -780,20 +819,19 @@ int __key_link_begin(struct key *keyring, const struct key_type *type, if (klist && klist->nkeys < klist->maxkeys) { /* there's sufficient slack space to append directly */ - nklist = NULL; + klist->delkey = klist->nkeys; prealloc = KEY_LINK_FIXQUOTA; } else { /* grow the key list */ max = 4; - if (klist) + if (klist) { max += klist->maxkeys; + if (max > MAX_KEYRING_LINKS) + max = MAX_KEYRING_LINKS; + BUG_ON(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); @@ -813,10 +851,10 @@ int __key_link_begin(struct key *keyring, const struct key_type *type, } /* add the key into the new space */ - nklist->keys[nklist->delkey] = NULL; + RCU_INIT_POINTER(nklist->keys[nklist->delkey], NULL); + prealloc = (unsigned long)nklist | KEY_LINK_FIXQUOTA; } - prealloc = (unsigned long)nklist | KEY_LINK_FIXQUOTA; done: *_prealloc = prealloc; kleave(" = 0"); @@ -862,6 +900,7 @@ void __key_link(struct key *keyring, struct key *key, unsigned long *_prealloc) { struct keyring_list *klist, *nklist; + struct key *discard; nklist = (struct keyring_list *)(*_prealloc & ~KEY_LINK_FIXQUOTA); *_prealloc = 0; @@ -871,14 +910,16 @@ void __key_link(struct key *keyring, struct key *key, klist = rcu_dereference_locked_keyring(keyring); atomic_inc(&key->usage); + keyring->last_used_at = key->last_used_at = + current_kernel_time().tv_sec; /* 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", + kdebug("reissue %hu/%hu/%hu", nklist->delkey, nklist->nkeys, nklist->maxkeys); - nklist->keys[nklist->delkey] = key; + RCU_INIT_POINTER(nklist->keys[nklist->delkey], key); rcu_assign_pointer(keyring->payload.subscriptions, nklist); @@ -889,9 +930,23 @@ void __key_link(struct key *keyring, struct key *key, klist->delkey, klist->nkeys, klist->maxkeys); call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); } + } else if (klist->delkey < klist->nkeys) { + kdebug("replace %hu/%hu/%hu", + klist->delkey, klist->nkeys, klist->maxkeys); + + discard = rcu_dereference_protected( + klist->keys[klist->delkey], + rwsem_is_locked(&keyring->sem)); + rcu_assign_pointer(klist->keys[klist->delkey], key); + /* The garbage collector will take care of RCU + * synchronisation */ + key_put(discard); } else { /* there's sufficient slack space to append directly */ - klist->keys[klist->nkeys] = key; + kdebug("append %hu/%hu/%hu", + klist->delkey, klist->nkeys, klist->maxkeys); + + RCU_INIT_POINTER(klist->keys[klist->delkey], key); smp_wmb(); klist->nkeys++; } @@ -998,7 +1053,7 @@ int key_unlink(struct key *keyring, struct key *key) if (klist) { /* search the keyring for the key */ for (loop = 0; loop < klist->nkeys; loop++) - if (klist->keys[loop] == key) + if (rcu_access_pointer(klist->keys[loop]) == key) goto key_is_present; } @@ -1061,7 +1116,7 @@ static void keyring_clear_rcu_disposal(struct rcu_head *rcu) klist = container_of(rcu, struct keyring_list, rcu); for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); + key_put(rcu_access_pointer(klist->keys[loop])); kfree(klist); } @@ -1128,15 +1183,6 @@ static void keyring_revoke(struct key *keyring) } /* - * Determine whether a key is dead. - */ -static bool key_is_dead(struct key *key, time_t limit) -{ - return test_bit(KEY_FLAG_DEAD, &key->flags) || - (key->expiry > 0 && key->expiry <= limit); -} - -/* * Collect garbage from the contents of a keyring, replacing the old list with * a new one with the pointers all shuffled down. * @@ -1161,7 +1207,8 @@ void keyring_gc(struct key *keyring, time_t limit) /* 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)) + if (!key_is_dead(rcu_deref_link_locked(klist, loop, keyring), + limit)) keep++; if (keep == klist->nkeys) @@ -1182,11 +1229,11 @@ void keyring_gc(struct key *keyring, time_t limit) */ keep = 0; for (loop = klist->nkeys - 1; loop >= 0; loop--) { - key = klist->keys[loop]; + key = rcu_deref_link_locked(klist, loop, keyring); if (!key_is_dead(key, limit)) { if (keep >= max) goto discard_new; - new->keys[keep++] = key_get(key); + RCU_INIT_POINTER(new->keys[keep++], key_get(key)); } } new->nkeys = keep; diff --git a/security/keys/permission.c b/security/keys/permission.c index 5442900d292..0b4d019e027 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -88,32 +88,29 @@ 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/proc.c b/security/keys/proc.c index 49bbc97943a..30d1ddfd9ce 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -242,7 +242,7 @@ 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), @@ -250,6 +250,7 @@ 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, diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 447fb7618ff..d71056db7b6 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -732,6 +732,8 @@ try_again: if (ret < 0) goto invalid_key; + key->last_used_at = current_kernel_time().tv_sec; + error: put_cred(cred); return key_ref; |