lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 15 Sep 2014 15:06:57 -0700
From:	Kamal Mostafa <>
Cc:	Stephen Hemminger <>,
	Neal Cardwell <>,
	Eric Dumazet <>,
	David Laight <David.Laight@...LAB.COM>,
	Doug Leith <>,
	Christoph Paasch <>,
	"David S. Miller" <>,
	Kamal Mostafa <>
Subject: [PATCH 3.13 007/187] tcp: Fix integer-overflow in TCP vegas -stable review patch.  If anyone has any objections, please let me know.


From: Christoph Paasch <>

[ 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 <>
Cc: Neal Cardwell <>
Cc: Eric Dumazet <>
Cc: David Laight <David.Laight@...LAB.COM>
Cc: Doug Leith <>
Fixes: 8d3a564da34e (tcp: tcp_vegas cong avoid fix)
Signed-off-by: Christoph Paasch <>
Signed-off-by: David S. Miller <>
Signed-off-by: Kamal Mostafa <>
 net/ipv4/tcp_vegas.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
index 06cae62..6b1a5fd 100644
--- a/net/ipv4/tcp_vegas.c
+++ b/net/ipv4/tcp_vegas.c
@@ -219,7 +219,8 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked,
 			 * 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

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists