From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754029AbcBNXrP (ORCPT ); Sun, 14 Feb 2016 18:47:15 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42866 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753858AbcBNWtA (ORCPT ); Sun, 14 Feb 2016 17:49:00 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Herbert Xu Subject: [PATCH 4.3 173/200] crypto: algif_hash - Fix race condition in hash_check_key Date: Sun, 14 Feb 2016 14:23:00 -0800 Message-Id: <20160214222223.611834838@linuxfoundation.org> X-Mailer: git-send-email 2.7.1 In-Reply-To: <20160214222217.084543173@linuxfoundation.org> References: <20160214222217.084543173@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Herbert Xu commit ad46d7e33219218605ea619e32553daf4f346b9f upstream. We need to lock the child socket in hash_check_key as otherwise two simultaneous calls can cause the parent socket to be freed. Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/algif_hash.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -242,22 +242,23 @@ static struct proto_ops algif_hash_ops = static int hash_check_key(struct socket *sock) { - int err; + int err = 0; struct sock *psk; struct alg_sock *pask; struct algif_hash_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; @@ -271,6 +272,8 @@ static int hash_check_key(struct socket unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; }