Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752613AbdFAQEk (ORCPT ); Thu, 1 Jun 2017 12:04:40 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33835 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752264AbdFAPpN (ORCPT ); Thu, 1 Jun 2017 11:45:13 -0400 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, "David S. Miller" , "Andrey Konovalov" , "Daniel Jiang" , "Eric Dumazet" , "Solar Designer" Date: Thu, 01 Jun 2017 16:43:16 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 185/212] ping: implement proper locking In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 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 Content-Length: 1585 Lines: 52 3.16.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream. We got a report of yet another bug in ping http://www.openwall.com/lists/oss-security/2017/03/24/6 ->disconnect() is not called with socket lock held. Fix this by acquiring ping rwlock earlier. Thanks to Daniel, Alexander and Andrey for letting us know this problem. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet Reported-by: Daniel Jiang Reported-by: Solar Designer Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv4/ping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -154,17 +154,18 @@ void ping_hash(struct sock *sk) void ping_unhash(struct sock *sk) { struct inet_sock *isk = inet_sk(sk); + pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); + write_lock_bh(&ping_table.lock); if (sk_hashed(sk)) { - write_lock_bh(&ping_table.lock); hlist_nulls_del(&sk->sk_nulls_node); sk_nulls_node_init(&sk->sk_nulls_node); sock_put(sk); isk->inet_num = 0; isk->inet_sport = 0; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - write_unlock_bh(&ping_table.lock); } + write_unlock_bh(&ping_table.lock); } EXPORT_SYMBOL_GPL(ping_unhash);