From: Christoph Paasch Date: Tue, 29 Jul 2014 10:07:27 +0000 (+0200) Subject: tcp: Fix integer-overflows in TCP veno X-Git-Tag: v3.15.10~19 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e2a4fd1e555c55487299c8d8d8946c12ea4cc4e;p=thirdparty%2Fkernel%2Fstable.git tcp: Fix integer-overflows in TCP veno [ 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 --- diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c index 1b8e28fcd7e1c..4cd4e1be3a71e 100644 --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -145,7 +145,7 @@ 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);