From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933284AbcBIAVP (ORCPT ); Mon, 8 Feb 2016 19:21:15 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59769 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755589AbcBHXyi (ORCPT ); Mon, 8 Feb 2016 18:54:38 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Herbert Xu" Date: Mon, 08 Feb 2016 23:53:51 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 80/87] crypto: algif_hash - Fix race condition in hash_check_key In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:a11:96ff:fe28:a980 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.77-rc1 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: Ben Hutchings --- crypto/algif_hash.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -253,22 +253,23 @@ 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; @@ -282,6 +283,8 @@ static int hash_check_key(struct socket unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; }