diff options
| author | Christoph Paasch <christoph.paasch@uclouvain.be> | 2014-07-29 13:40:57 +0200 |
|---|---|---|
| committer | Stefan Bader <stefan.bader@canonical.com> | 2014-11-25 15:20:26 +0100 |
| commit | e710d15f1a1d15a4e21f5655e7d2b73a58fefa67 (patch) | |
| tree | df214a6062ff461a204e154f20d654edc2171842 | |
| parent | 0f98eba2af1b0ebb233ce06e09db273d9321dbe4 (diff) | |
| download | linux-2.6.32.y-drm33.z-e710d15f1a1d15a4e21f5655e7d2b73a58fefa67.tar.gz | |
tcp: Fix integer-overflow in TCP vegas
[ Upstream commit 1f74e613ded11517db90b2bd57e9464d9e0fb161 ]
In vegas 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.
Then, we need to do do_div to allow this to be used on 32-bit arches.
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Doug Leith <doug.leith@nuim.ie>
Fixes: 8d3a564da34e (tcp: tcp_vegas cong avoid fix)
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
| -rw-r--r-- | net/ipv4/tcp_vegas.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c index c6743eec9b7d0c..3044e40ede5428 100644 --- a/net/ipv4/tcp_vegas.c +++ b/net/ipv4/tcp_vegas.c @@ -218,7 +218,8 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) * This is: * (actual rate in segments) * baseRTT */ - target_cwnd = tp->snd_cwnd * vegas->baseRTT / rtt; + target_cwnd = (u64)tp->snd_cwnd * vegas->baseRTT; + do_div(target_cwnd, rtt); /* Calculate the difference between the window we had, * and the window we would like to have. This quantity |