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authorDavid Howells <dhowells@redhat.com>2010-04-23 13:18:00 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-04-24 11:31:25 -0700
commit93b4a44f3ad69520d605aace3f3486b8eb754b96 (patch)
tree8eb946db950ccc6aee1d00b226739f44141dd310
parentccdb40048b2972f10bdc944913c0e0ee26b5d1f2 (diff)
keys: fix an RCU warning
Fix the following RCU warning: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- security/keys/request_key.c:116 invoked rcu_dereference_check() without protection! This was caused by doing: [root@andromeda ~]# keyctl newring fred @s 539196288 [root@andromeda ~]# keyctl request2 user a a 539196288 request_key: Required key not available Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--security/keys/request_key.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 03fe63ed55b..ea97c3120d6 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -68,7 +68,8 @@ static int call_sbin_request_key(struct key_construction *cons,
{
const struct cred *cred = current_cred();
key_serial_t prkey, sskey;
- struct key *key = cons->key, *authkey = cons->authkey, *keyring;
+ struct key *key = cons->key, *authkey = cons->authkey, *keyring,
+ *session;
char *argv[9], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
char desc[20];
@@ -112,10 +113,12 @@ static int call_sbin_request_key(struct key_construction *cons,
if (cred->tgcred->process_keyring)
prkey = cred->tgcred->process_keyring->serial;
- if (cred->tgcred->session_keyring)
- sskey = rcu_dereference(cred->tgcred->session_keyring)->serial;
- else
- sskey = cred->user->session_keyring->serial;
+ rcu_read_lock();
+ session = rcu_dereference(cred->tgcred->session_keyring);
+ if (!session)
+ session = cred->user->session_keyring;
+ sskey = session->serial;
+ rcu_read_unlock();
sprintf(keyring_str[2], "%d", sskey);