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,
.def_datalen = sizeof(struct keyring_list),
.instantiate = keyring_instantiate,
.match = keyring_match,
+ .revoke = keyring_revoke,
.destroy = keyring_destroy,
.describe = keyring_describe,
.read = keyring_read,
* semaphore to serialise link/link calls to prevent two link calls in parallel
* introducing a cycle
*/
-DECLARE_RWSEM(keyring_serialise_link_sem);
+static DECLARE_RWSEM(keyring_serialise_link_sem);
/*****************************************************************************/
/*
* allocate a keyring and link into the destination keyring
*/
struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
- int not_in_quota, struct key *dest)
+ struct task_struct *ctx, unsigned long flags,
+ struct key *dest)
{
struct key *keyring;
int ret;
keyring = key_alloc(&key_type_keyring, description,
- uid, gid,
+ 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);
/*
* search the given keyring only (no recursion)
* - keyring must be locked by caller
+ * - caller must guarantee that the keyring is a keyring
*/
key_ref_t __keyring_search_one(key_ref_t keyring_ref,
const struct key_type *ktype,
} /* end __keyring_search_one() */
-/*****************************************************************************/
-/*
- * search for an instantiation authorisation key matching a target key
- * - the RCU read lock must be held by the caller
- * - a target_id of zero specifies any valid token
- */
-struct key *keyring_search_instkey(struct key *keyring,
- key_serial_t target_id)
-{
- struct request_key_auth *rka;
- struct keyring_list *klist;
- struct key *instkey;
- int loop;
-
- klist = rcu_dereference(keyring->payload.subscriptions);
- if (klist) {
- for (loop = 0; loop < klist->nkeys; loop++) {
- instkey = klist->keys[loop];
-
- if (instkey->type != &key_type_request_key_auth)
- continue;
-
- rka = instkey->payload.data;
- if (target_id && rka->target_key->serial != target_id)
- continue;
-
- /* the auth key is revoked during instantiation */
- if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags))
- goto found;
-
- instkey = ERR_PTR(-EKEYREVOKED);
- goto error;
- }
- }
-
- instkey = ERR_PTR(-EACCES);
- goto error;
-
-found:
- atomic_inc(&instkey->usage);
-error:
- return instkey;
-
-} /* end keyring_search_instkey() */
-
/*****************************************************************************/
/*
* find a keyring with the specified name
} /* end keyring_link_rcu_disposal() */
+/*****************************************************************************/
+/*
+ * dispose of a keyring list after the RCU grace period, freeing the unlinked
+ * key
+ */
+static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
+{
+ struct keyring_list *klist =
+ container_of(rcu, struct keyring_list, rcu);
+
+ key_put(klist->keys[klist->delkey]);
+ kfree(klist);
+
+} /* end keyring_unlink_rcu_disposal() */
+
/*****************************************************************************/
/*
* link a key into to a keyring
* - must be called with the keyring's semaphore write-locked
+ * - discard already extant link to matching key if there is one
*/
int __key_link(struct key *keyring, struct key *key)
{
struct keyring_list *klist, *nklist;
unsigned max;
size_t size;
- int ret;
+ int loop, ret;
ret = -EKEYREVOKED;
if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
goto error2;
}
+ /* see if there's a matching key we can displace */
+ klist = keyring->payload.subscriptions;
+
+ if (klist && klist->nkeys > 0) {
+ struct key_type *type = key->type;
+
+ for (loop = klist->nkeys - 1; loop >= 0; loop--) {
+ if (klist->keys[loop]->type == type &&
+ strcmp(klist->keys[loop]->description,
+ key->description) == 0
+ ) {
+ /* found a match - replace with new key */
+ size = sizeof(struct key *) * klist->maxkeys;
+ size += sizeof(*klist);
+ BUG_ON(size > PAGE_SIZE);
+
+ ret = -ENOMEM;
+ nklist = kmalloc(size, GFP_KERNEL);
+ if (!nklist)
+ goto error2;
+
+ memcpy(nklist, klist, size);
+
+ /* replace matched key */
+ atomic_inc(&key->usage);
+ nklist->keys[loop] = key;
+
+ rcu_assign_pointer(
+ keyring->payload.subscriptions,
+ nklist);
+
+ /* dispose of the old keyring list and the
+ * displaced key */
+ klist->delkey = loop;
+ call_rcu(&klist->rcu,
+ keyring_unlink_rcu_disposal);
+
+ goto done;
+ }
+ }
+ }
+
/* check that we aren't going to overrun the user's quota */
ret = key_payload_reserve(keyring,
keyring->datalen + KEYQUOTA_LINK_BYTES);
smp_wmb();
klist->nkeys++;
smp_wmb();
-
- ret = 0;
}
else {
/* grow the key list */
/* dispose of the old keyring list */
if (klist)
call_rcu(&klist->rcu, keyring_link_rcu_disposal);
-
- ret = 0;
}
- error2:
+done:
+ ret = 0;
+error2:
up_write(&keyring_serialise_link_sem);
- error:
+error:
return ret;
- error3:
+error3:
/* undo the quota changes */
key_payload_reserve(keyring,
keyring->datalen - KEYQUOTA_LINK_BYTES);
EXPORT_SYMBOL(key_link);
-/*****************************************************************************/
-/*
- * dispose of a keyring list after the RCU grace period, freeing the unlinked
- * key
- */
-static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
-{
- struct keyring_list *klist =
- container_of(rcu, struct keyring_list, rcu);
-
- key_put(klist->keys[klist->delkey]);
- kfree(klist);
-
-} /* end keyring_unlink_rcu_disposal() */
-
/*****************************************************************************/
/*
* unlink the first link to a key from a 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() */