Bug 755584 - (CVE-2011-4326) CVE-2011-4326 kernel: wrong headroom check in udp6_ufo_fragment()
CVE-2011-4326 kernel: wrong headroom check in udp6_ufo_fragment()
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
All Linux
high Severity high
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Assigned To: Red Hat Product Security
: Security
Depends On: 698170 753167 755589 755590 761341
Blocks: 755624
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Reported: 2011-11-21 09:36 EST by Petr Matousek
Modified: 2016-11-08 10:56 EST (History)
25 users (show)

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Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Last Closed: 2012-03-28 04:41:27 EDT
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RHEL 7.3 requirements from Atomic Host:
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Description Petr Matousek 2011-11-21 09:36:26 EST
A bug was found in the way headroom check was performed in udp6_ufo_fragment() function. A remote attacker could use this flaw to crash the system.

Upstream patch:
Comment 1 Petr Matousek 2011-11-21 09:37:24 EST
Details (copied from 682066#c0):

The kernel panic occurs if a bridge device is connected with physical NIC and
UDP packets are transmitted via the bridge device.

The kernel panic occurs when all the following conditions consist:
- The kernel version is RHEL6(2.6.32-71.xx.el6).
- The NETIF_F_HW_CSUM of the physical device connected with the bridge device
is available.
- The udp-fragmentation-offload function of the bridge device is available(ON).
- The udp-fragmentation-offload function of the physical NIC is
- IPv6 protocol
- The size of the UDP datagram exceeds MTU. (fragmentation is necessary)
Comment 3 Petr Matousek 2011-11-21 09:41:30 EST
Created kernel tracking bugs for this issue

Affects: fedora-all [bug 755590]
Comment 5 Petr Matousek 2011-11-21 09:50:22 EST

This issue did not affect the versions of Linux kernel as shipped with Red Hat
Enterprise Linux 4 and 5 as they did not provide support for UDP Fragmentation Offload (UFO) functionality. This has been addressed in Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG via https://rhn.redhat.com/errata/RHSA-2011-1465.html, and https://rhn.redhat.com/errata/RHSA-2012-0010.html.
Comment 6 errata-xmlrpc 2011-11-22 11:53:44 EST
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:1465 https://rhn.redhat.com/errata/RHSA-2011-1465.html
Comment 7 Fedora Update System 2011-11-28 19:21:53 EST
kernel- has been pushed to the Fedora 14 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 9 errata-xmlrpc 2012-01-10 15:17:12 EST
This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2012:0010 https://rhn.redhat.com/errata/RHSA-2012-0010.html

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