From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751916AbaKPWBE (ORCPT ); Sun, 16 Nov 2014 17:01:04 -0500 Received: from 1wt.eu ([62.212.114.60]:47937 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750938AbaKPWA5 (ORCPT ); Sun, 16 Nov 2014 17:00:57 -0500 Message-Id: <20141116215329.617534929@1wt.eu> User-Agent: quilt/0.48-1 Date: Sun, 16 Nov 2014 22:53:51 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christoph Paasch , "David S. Miller" , Willy Tarreau Subject: [ 23/48] tcp: Fix integer-overflows in TCP veno In-Reply-To: <28c765bc23bd4bae1611534e510f49f8@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Paasch [ Upstream commit 45a07695bc64b3ab5d6d2215f9677e5b8c05a7d0 ] In veno we do a multiplication of the cwnd and the rtt. This may overflow and thus their result is stored in a u64. However, we first need to cast the cwnd so that actually 64-bit arithmetic is done. A first attempt at fixing 76f1017757aa0 ([TCP]: TCP Veno congestion control) was made by 159131149c2 (tcp: Overflow bug in Vegas), but it failed to add the required cast in tcp_veno_cong_avoid(). Fixes: 76f1017757aa0 ([TCP]: TCP Veno congestion control) Signed-off-by: Christoph Paasch Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- net/ipv4/tcp_veno.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c index e9bbff7..8d395a3 100644 --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -144,7 +144,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) rtt = veno->minrtt; - target_cwnd = (tp->snd_cwnd * veno->basertt); + target_cwnd = (u64)tp->snd_cwnd * veno->basertt; target_cwnd <<= V_PARAM_SHIFT; do_div(target_cwnd, rtt); -- 1.7.12.2.21.g234cd45.dirty