Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Wed, 13 Nov 2013 18:34:38 +0100
From: Petr Matousek <pmatouse@...hat.com>
To: oss-security@...ts.openwall.com
Cc: Kurt Seifried <kseifrie@...hat.com>, Saran.Neti@...us.com
Subject: CVE-2013-4563 -- Linux kernel: net: large udp packet over IPv6 over
 UFO-enabled device with TBF qdisc panic

Commit 1e2bd517c108816220f262d7954b697af03b5f9c ("udp6: Fix udp
fragmentation for tunnel traffic.") changed the calculation if
there is enough space to include a fragment header in the skb from a
skb->mac_header dervived one to skb_headroom. Because we already peeled
off the skb to transport_header this is wrong.

This fixes a panic Saran Neti reported. He used the tbf scheduler which
skb_gso_segments the skb. The offsets get negative and we panic in
memcpy because the skb was erroneously not expanded at the head.

Introduced by:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1e2bd517c108816220f262d7954b697af03b5f9c

Introduced in:
v3.10-rc5

Upstream fix:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0e033e0

References:
http://marc.info/?l=linux-netdev&m=138305762205012&w=2
https://bugzilla.redhat.com/show_bug.cgi?id=1030015

Acknowledgements:

Red Hat would like to thank Saran Neti of TELUS Security Labs for
reporting this issue.

Thanks,
-- 
Petr Matousek / Red Hat Security Response Team

Content of type "application/pgp-signature" skipped

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.