Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753529AbdFSTJl (ORCPT + 2 others); Mon, 19 Jun 2017 15:09:41 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52419 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750946AbdFSSgu (ORCPT ); Mon, 19 Jun 2017 14:36:50 -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 3.10 230/268] net/packet: fix overflow in check for priv area size Date: Mon, 19 Jun 2017 20:32:09 +0200 Message-Id: <1497897167-14556-231-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 2b6867c2ce76c596676bec7d2d525af525fdc6e2 upstream. Subtracting tp_sizeof_priv from tp_block_size and casting to int to check whether one is less then the other doesn't always work (both of them are unsigned ints). Compare them as is instead. Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as it can overflow inside BLK_PLUS_PRIV otherwise. 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 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8bb77e0..4a477a5 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3672,8 +3672,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, if (unlikely(req->tp_block_size & (PAGE_SIZE - 1))) goto out; if (po->tp_version >= TPACKET_V3 && - (int)(req->tp_block_size - - BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) + req->tp_block_size <= + BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv)) goto out; if (unlikely(req->tp_frame_size < po->tp_hdrlen + po->tp_reserve)) -- 2.8.0.rc2.1.gbe9624a