From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932565AbcHNK6Q (ORCPT ); Sun, 14 Aug 2016 06:58:16 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51844 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932441AbcHNK6K (ORCPT ); Sun, 14 Aug 2016 06:58:10 -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, "Antonio Quartulli" , "Marek Lindner" , "Sven Eckelmann" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 101/305] batman-adv: Fix integer overflow in batadv_iv_ogm_calc_tq In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 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 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit d285f52cc0f23564fd61976d43fd5b991b4828f6 upstream. The undefined behavior sanatizer detected an signed integer overflow in a setup with near perfect link quality UBSAN: Undefined behaviour in net/batman-adv/bat_iv_ogm.c:1246:25 signed integer overflow: 8713350 * 255 cannot be represented in type 'int' The problems happens because the calculation of mixed unsigned and signed integers resulted in an integer multiplication. batadv_ogm_packet::tq (u8 255) * tq_own (u8 255) * tq_asym_penalty (int 134; max 255) * tq_iface_penalty (int 255; max 255) The tq_iface_penalty, tq_asym_penalty and inv_asym_penalty can just be changed to unsigned int because they are not expected to become negative. Fixes: c039876892e3 ("batman-adv: add WiFi penalty") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/batman-adv/bat_iv_ogm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -1134,9 +1134,10 @@ static int batadv_iv_ogm_calc_tq(struct uint8_t total_count; uint8_t orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own; unsigned int neigh_rq_inv_cube, neigh_rq_max_cube; - int tq_asym_penalty, inv_asym_penalty, if_num, ret = 0; + int if_num, ret = 0; + unsigned int tq_asym_penalty, inv_asym_penalty; unsigned int combined_tq; - int tq_iface_penalty; + unsigned int tq_iface_penalty; /* find corresponding one hop neighbor */ rcu_read_lock();