From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752495AbeE3LHC (ORCPT ); Wed, 30 May 2018 07:07:02 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60629 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591AbeE3LG4 (ORCPT ); Wed, 30 May 2018 07:06:56 -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, "Pablo Neira Ayuso" , "Florian Westphal" Date: Wed, 30 May 2018 11:52:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 005/153] netfilter: ebtables: fix erroneous reject of last rule 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 3.2.102-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 932909d9b28d27e807ff8eecb68c7748f6701628 upstream. The last rule in the blob has next_entry offset that is same as total size. This made "ebtables32 -A OUTPUT -d de:ad:be:ef:01:02" fail on 64 bit kernel. Fixes: b71812168571fa ("netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Ben Hutchings --- net/bridge/netfilter/ebtables.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -2064,8 +2064,12 @@ static int size_entry_mwt(struct ebt_ent * offsets are relative to beginning of struct ebt_entry (i.e., 0). */ for (i = 0; i < 4 ; ++i) { - if (offsets[i] >= *total) + if (offsets[i] > *total) return -EINVAL; + + if (i < 3 && offsets[i] == *total) + return -EINVAL; + if (i == 0) continue; if (offsets[i-1] > offsets[i])