Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753550AbdFSTKv (ORCPT + 2 others); Mon, 19 Jun 2017 15:10:51 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52390 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753397AbdFSSgl (ORCPT ); Mon, 19 Jun 2017 14:36:41 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Andrey Konovalov , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 248/268] net/packet: fix overflow in check for tp_frame_nr Date: Mon, 19 Jun 2017 20:32:27 +0200 Message-Id: <1497897167-14556-249-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Andrey Konovalov 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: Willy Tarreau --- 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 4a477a5..cea85d8 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3684,6 +3684,8 @@ 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; -- 2.8.0.rc2.1.gbe9624a