crypto: algif_hash - Fix race condition in hash_check_key

We need to lock the child socket in hash_check_key as otherwise
two simultaneous calls can cause the parent socket to be freed.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2016-01-15 22:01:08 +08:00
parent cbafd643be
commit ad46d7e332

View File

@ -242,22 +242,23 @@ static struct proto_ops algif_hash_ops = {
static int hash_check_key(struct socket *sock)
{
int err;
int err = 0;
struct sock *psk;
struct alg_sock *pask;
struct algif_hash_tfm *tfm;
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
lock_sock(sk);
if (ask->refcnt)
return 0;
goto unlock_child;
psk = ask->parent;
pask = alg_sk(ask->parent);
tfm = pask->private;
err = -ENOKEY;
lock_sock(psk);
lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
if (!tfm->has_key)
goto unlock;
@ -271,6 +272,8 @@ static int hash_check_key(struct socket *sock)
unlock:
release_sock(psk);
unlock_child:
release_sock(sk);
return err;
}