FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.

» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Debian > Debian Kernel

LinkBack Thread Tools
Old 11-11-2010, 01:14 PM
Ben Hutchings
Default Bug#603158: possible kernel oops from user MSS

Package: linux-2.6
Version: 2.6.28-1
Severity: serious
Tags: security patch upstream

This bug was introduced in upstream version 2.6.28 and is about to be
fixed in 2.6.37. I don't think any CVE has been assigned yet.


----- Forwarded message from David Miller <davem@davemloft.net> -----

From: David Miller <davem@davemloft.net>
To: shanwei@cn.fujitsu.com
Cc: schen@mvista.com, netdev@vger.kernel.org
Subject: Re: possible kernel oops from user MSS
Date: Thu, 11 Nov 2010 13:40:18 +0000

From: David Miller <davem@davemloft.net>
Date: Wed, 10 Nov 2010 21:33:13 -0800 (PST)

> I'll make the minimum 64 or something like that.

Here is the patch I will use:

tcp: Increase TCP_MAXSEG socket option minimum.

As noted by Steve Chen, since commit
f5fff5dc8a7a3f395b0525c02ba92c95d42b7390 ("tcp: advertise MSS
requested by user") we can end up with a situation where
tcp_select_initial_window() does a divide by a zero (or
even negative) mss value.

The problem is that sometimes we effectively subtract

Fix this by increasing the minimum from 8 to 64.

Reported-by: Steve Chen <schen@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 245603c..0814199 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2246,7 +2246,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
/* Values greater than interface MTU won't take effect. However
* at the point when this call is done we typically don't yet
* know which interface is going to be used */
- if (val < 8 || val > MAX_TCP_WINDOW) {
+ if (val < 64 || val > MAX_TCP_WINDOW) {
err = -EINVAL;

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html

----- End forwarded message -----

Ben Hutchings
We get into the habit of living before acquiring the habit of thinking.
- Albert Camus

To UNSUBSCRIBE, email to debian-kernel-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Archive: 20101111141445.GH31963@decadent.org.uk">http://lists.debian.org/20101111141445.GH31963@decadent.org.uk

Thread Tools

All times are GMT. The time now is 08:58 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org