From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941422AbcKNDl1 (ORCPT ); Sun, 13 Nov 2016 22:41:27 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45317 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752857AbcKNCER (ORCPT ); Sun, 13 Nov 2016 21:04:17 -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, "Simon Wunderlich" , "Marek Lindner" , "Sven Eckelmann" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 034/346] batman-adv: Avoid nullptr dereference in bla after vlan_insert_tag In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 10c78f5854d361ded4736c1831948e0a5f67b932 upstream. vlan_insert_tag can return NULL on errors. The bridge loop avoidance code therefore has to check the return value of vlan_insert_tag for NULL before it can safely operate on this pointer. Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Simon Wunderlich Signed-off-by: Ben Hutchings --- net/batman-adv/bridge_loop_avoidance.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -338,9 +338,12 @@ static void batadv_bla_send_claim(struct break; } - if (vid & BATADV_VLAN_HAS_TAG) + if (vid & BATADV_VLAN_HAS_TAG) { skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); + if (!skb) + goto out; + } skb_reset_mac_header(skb); skb->protocol = eth_type_trans(skb, soft_iface);