From 45a07695bc64b3ab5d6d2215f9677e5b8c05a7d0 Mon Sep 17 00:00:00 2001 From: Christoph Paasch Date: Tue, 29 Jul 2014 12:07:27 +0200 Subject: [PATCH] tcp: Fix integer-overflows in TCP veno 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 --- 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 27b9825..8276977 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 acked) 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); -- 2.7.4