From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932482AbdEDJNm (ORCPT ); Thu, 4 May 2017 05:13:42 -0400 Received: from mx2.suse.de ([195.135.220.15]:59812 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753545AbdEDJGj (ORCPT ); Thu, 4 May 2017 05:06:39 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrey Konovalov , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 63/86] net/packet: fix overflow in check for tp_frame_nr Date: Thu, 4 May 2017 11:04:28 +0200 Message-Id: <5bc3dfa62110b38bb11a6a96a805dc1355fdcd56.1493888632.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.2 In-Reply-To: <13a6a971c9165237531c2870da03084a6becc905.1493888632.git.jslaby@suse.cz> References: <13a6a971c9165237531c2870da03084a6becc905.1493888632.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Konovalov 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 8f8d28e4d6d815a391285e121c3a53a0b6cb9e7b upstream. When calculating rb->frames_per_block * req->tp_block_nr the result can overflow. Add a check that tp_block_size * tp_block_nr <= UINT_MAX. Since frames_per_block <= tp_block_size, the expression would never overflow. Signed-off-by: Andrey Konovalov Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/packet/af_packet.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ed1fed3330af..d6087b4359cc 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3665,6 +3665,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, rb->frames_per_block = req->tp_block_size/req->tp_frame_size; if (unlikely(rb->frames_per_block <= 0)) goto out; + if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr)) + goto out; if (unlikely((rb->frames_per_block * req->tp_block_nr) != req->tp_frame_nr)) goto out; -- 2.12.2