From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Ryabinin Subject: [PATCH stable 3.10.y 14/18] crypto: algif_skcipher - Fix race condition in skcipher_check_key Date: Thu, 27 Oct 2016 17:29:47 +0300 Message-ID: <1477578591-28924-15-git-send-email-aryabinin@virtuozzo.com> References: <1477578591-28924-1-git-send-email-aryabinin@virtuozzo.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , , Andrey Ryabinin To: Willy Tarreau , Return-path: Received: from mail-ve1eur01on0103.outbound.protection.outlook.com ([104.47.1.103]:14496 "EHLO EUR01-VE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934208AbcJ0RCY (ORCPT ); Thu, 27 Oct 2016 13:02:24 -0400 In-Reply-To: <1477578591-28924-1-git-send-email-aryabinin@virtuozzo.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Herbert Xu 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: Andrey Ryabinin --- 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 a7800b7..13fd26e 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; } -- 2.7.3