Bug 212144 - CVE-2006-6535 unbalanced local_bh_enable() in dev_queue_xmit()
Summary: CVE-2006-6535 unbalanced local_bh_enable() in dev_queue_xmit()
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel
Version: 4.4
Hardware: All
OS: Linux
Target Milestone: ---
: ---
Assignee: Neil Horman
QA Contact: Brian Brock
Whiteboard: impact=moderate,source=bugzilla,repor...
Depends On:
TreeView+ depends on / blocked
Reported: 2006-10-25 10:53 UTC by Vasily Averin
Modified: 2008-01-09 17:29 UTC (History)
2 users (show)

Fixed In Version: RHSA-2007-0014
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2007-01-30 14:28:55 UTC
Target Upstream Version:

Attachments (Terms of Use)
this patch fixes unbalanced local_bh_enable() in dev_queue_xmit() (673 bytes, patch)
2006-10-25 10:54 UTC, Vasily Averin
no flags Details | Diff

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2007:0014 0 normal SHIPPED_LIVE Important: kernel security update 2007-01-30 14:25:00 UTC

Description Vasily Averin 2006-10-25 10:53:59 UTC
Kostantin Khorenko from OpenVZ/Virtuozzo linux kernel team has noticed the
following issue on RHEL4 (2.6.9-42.0.3 and 2.6.9-42.19) kernels.

dev_queue_xmit() have wrong error path: this function can fail before
local_bh_disable() call. In this case it jumps to out_kfree_skb label where it
calls local_bh_enable(). As a result it can lead to the data corruptions and the
node lockups.

This issue was fixed in linux mainstream by the following patches:

We are not sure that it can be user-exploitable, however from our point of view
it can happen on some hardware and software setups.

Comment 1 Vasily Averin 2006-10-25 10:54:00 UTC
Created attachment 139333 [details]
this patch fixes unbalanced local_bh_enable() in dev_queue_xmit()

Comment 2 Neil Horman 2006-11-07 21:07:29 UTC
looks reasonable.  I'll review it further in the AM.  thanks!

Comment 3 Jason Baron 2006-11-21 21:22:19 UTC
committed in stream U5 build 42.26. A test kernel with this patch is available
from http://people.redhat.com/~jbaron/rhel4/

Comment 4 Jason Baron 2006-12-18 21:43:58 UTC
committed in stream E5 build 42.0.4

Comment 6 Mike Gahagan 2007-01-17 20:48:02 UTC
I can confirm that the fix is in the 42.0.6 kernel.

Comment 8 Red Hat Bugzilla 2007-01-30 14:28:55 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


Note You need to log in before you can comment on or make changes to this bug.