From 7855e916590ab8d97abcba3d0dc735bcfa55561d Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 26 Feb 2016 12:44:11 +0100 Subject: crypto: algif_skcipher - Fix race condition in skcipher_check_key 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. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- crypto/algif_skcipher.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'crypto') diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 9cf9aa5df432..d2cacc7f079f 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -551,22 +551,23 @@ 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; @@ -580,6 +581,8 @@ static int skcipher_check_key(struct socket *sock) unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; } -- cgit v1.2.3