From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968347AbcA0VUd (ORCPT ); Wed, 27 Jan 2016 16:20:33 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43326 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161198AbcA0UjD (ORCPT ); Wed, 27 Jan 2016 15:39:03 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Herbert Xu , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 161/268] crypto: algif_skcipher - Fix race condition in skcipher_check_key Date: Wed, 27 Jan 2016 12:33:42 -0800 Message-Id: <1453926929-17663-162-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1453926929-17663-1-git-send-email-kamal@canonical.com> References: <1453926929-17663-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ 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. Signed-off-by: Herbert Xu Signed-off-by: Kamal Mostafa --- 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 8d4bf6e..74ffe56 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -756,22 +756,23 @@ 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; @@ -785,6 +786,8 @@ static int skcipher_check_key(struct socket *sock) unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; } -- 1.9.1