Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 096/117] crypto: algif_skcipher - Fix race condition in skcipher_check_key | Date | Sun, 14 Feb 2016 14:22:13 -0800 |
| |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Herbert Xu <herbert@gondor.apana.org.au>
commit 1822793a523e5d5730b19cc21160ff1717421bc8 upstream.
We need to lock the child socket in skcipher_check_key as otherwise two simultaneous calls can cause the parent socket to be freed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- crypto/algif_skcipher.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -755,22 +755,23 @@ static struct proto_ops algif_skcipher_o 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 soc unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; }
| |