From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752711AbdBETQd (ORCPT + 2 others); Sun, 5 Feb 2017 14:16:33 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:27287 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752194AbdBETQa (ORCPT ); Sun, 5 Feb 2017 14:16:30 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Herbert Xu , Andrey Ryabinin , Willy Tarreau Subject: [PATCH 3.10 017/319] crypto: algif_skcipher - Fix race condition in skcipher_check_key Date: Sun, 5 Feb 2017 20:09:21 +0100 Message-Id: <1486322063-7558-18-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322063-7558-1-git-send-email-w@1wt.eu> References: <1486322063-7558-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 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 Signed-off-by: Willy Tarreau --- 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; } -- 2.8.0.rc2.1.gbe9624a