From 9bc37ed5b25642391d5c39e9723c8cda1f5ccf39 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 15 Jan 2016 22:02:20 +0800 Subject: [PATCH] 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. Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings --- crypto/algif_skcipher.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 397205c98d3e..a9f42010d432 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; } -- 2.39.2