diff options
| -rw-r--r-- | security/keys/keyring.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 0b27271c670..1e4b0037935 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -20,6 +20,11 @@ #include <asm/uaccess.h> #include "internal.h" +#define rcu_dereference_locked_keyring(keyring) \ + (rcu_dereference_protected( \ + (keyring)->payload.subscriptions, \ + rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) + /* * when plumbing the depths of the key tree, this sets a hard limit set on how * deep we're willing to go @@ -201,8 +206,7 @@ static long keyring_read(const struct key *keyring, int loop, ret; ret = 0; - klist = keyring->payload.subscriptions; - + klist = rcu_dereference_locked_keyring(keyring); if (klist) { /* calculate how much data we could return */ qty = klist->nkeys * sizeof(key_serial_t); @@ -720,8 +724,7 @@ int __key_link(struct key *keyring, struct key *key) } /* see if there's a matching key we can displace */ - klist = keyring->payload.subscriptions; - + klist = rcu_dereference_locked_keyring(keyring); if (klist && klist->nkeys > 0) { struct key_type *type = key->type; @@ -765,8 +768,6 @@ int __key_link(struct key *keyring, struct key *key) if (ret < 0) goto error2; - klist = keyring->payload.subscriptions; - if (klist && klist->nkeys < klist->maxkeys) { /* there's sufficient slack space to add directly */ atomic_inc(&key->usage); @@ -868,7 +869,7 @@ int key_unlink(struct key *keyring, struct key *key) down_write(&keyring->sem); - klist = keyring->payload.subscriptions; + klist = rcu_dereference_locked_keyring(keyring); if (klist) { /* search the keyring for the key */ for (loop = 0; loop < klist->nkeys; loop++) @@ -959,7 +960,7 @@ int keyring_clear(struct key *keyring) /* detach the pointer block with the locks held */ down_write(&keyring->sem); - klist = keyring->payload.subscriptions; + klist = rcu_dereference_locked_keyring(keyring); if (klist) { /* adjust the quota */ key_payload_reserve(keyring, @@ -991,7 +992,9 @@ EXPORT_SYMBOL(keyring_clear); */ static void keyring_revoke(struct key *keyring) { - struct keyring_list *klist = keyring->payload.subscriptions; + struct keyring_list *klist; + + klist = rcu_dereference_locked_keyring(keyring); /* adjust the quota */ key_payload_reserve(keyring, 0); @@ -1025,7 +1028,7 @@ void keyring_gc(struct key *keyring, time_t limit) down_write(&keyring->sem); - klist = keyring->payload.subscriptions; + klist = rcu_dereference_locked_keyring(keyring); if (!klist) goto no_klist; |