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authorHerbert Xu <herbert@gondor.apana.org.au>2016-01-15 22:02:20 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2016-01-18 18:16:34 +0800
commit1822793a523e5d5730b19cc21160ff1717421bc8 (patch)
tree32a11267ee28dc0f2b22d4748b0c40788ed99fc1
parentad46d7e33219218605ea619e32553daf4f346b9f (diff)
downloadlinux-1822793a523e5d5730b19cc21160ff1717421bc8.tar.bz2
crypto: algif_skcipher - Fix race condition in skcipher_check_key
We need to lock the child socket in skcipher_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>
-rw-r--r--crypto/algif_skcipher.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 1f99d2d47715..dfff8b0b56df 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -755,22 +755,23 @@ static struct proto_ops algif_skcipher_ops = {
static int skcipher_check_key(struct socket *sock)
{
- int err;
+ int err = 0;
struct sock *psk;
struct alg_sock *pask;
struct skcipher_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;
@@ -784,6 +785,8 @@ static int skcipher_check_key(struct socket *sock)
unlock:
release_sock(psk);
+unlock_child:
+ release_sock(sk);
return err;
}