From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Paasch , "David S. Miller" Subject: [PATCH 3.15 08/26] tcp: Fix integer-overflows in TCP veno Date: Fri, 8 Aug 2014 14:35:15 -0700 Message-Id: <20140808213414.007465630@linuxfoundation.org> In-Reply-To: <20140808213413.648794968@linuxfoundation.org> References: <20140808213413.648794968@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.15-stable 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: Greg Kroah-Hartman --- net/ipv4/tcp_veno.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -145,7 +145,7 @@ static void tcp_veno_cong_avoid(struct s 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);