Bug 607054 (CVE-2010-2495) - CVE-2010-2495 kernel: l2tp: Fix oops in pppol2tp_xmit
Summary: CVE-2010-2495 kernel: l2tp: Fix oops in pppol2tp_xmit
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2010-2495
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 607055
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-06-23 03:54 UTC by Eugene Teo (Security Response)
Modified: 2019-09-29 12:37 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-03-28 08:36:36 UTC


Attachments (Terms of Use)

Description Eugene Teo (Security Response) 2010-06-23 03:54:44 UTC
Description of problem:
When transmitting L2TP frames, we derive the outgoing interface's UDP checksum hardware assist capabilities from the tunnel dst dev. This can sometimes be NULL, especially when routing protocols are used and routing changes occur. This patch just checks for NULL dst or dev pointers when checking for netdev hardware assist features.
    
BUG: unable to handle kernel NULL pointer dereference at 0000000c
IP: [<f89d074c>] pppol2tp_xmit+0x341/0x4da [pppol2tp]
*pde = 00000000
Oops: 0000 [#1] SMP
last sysfs file: /sys/class/net/lo/operstate
Modules linked in: pppol2tp pppox ppp_generic slhc ipv6 dummy loop snd_hda_codec_atihdmi snd_hda_intel snd_hda_codec snd_
[...]
    Code: 8d 45 08 f0 ff 45 08 89 6b 08 c7 43 68 7e fb 9c f8 8a 45 24 83 e0 0c 3c 04 75 09 80 63 64 f3 e9 b4 00 00 00 8b 43 1
    EIP: [<f89d074c>] pppol2tp_xmit+0x341/0x4da [pppol2tp] SS:ESP 0068:f70a9cac
    CR2: 000000000000000c

Introduced in ffcebb16 (v2.6.29-rc1~581), fixed in 3feec909 (fixed in v2.6.34-rc2).

Upstream commit:
http://git.kernel.org/linus/ffcebb16
http://git.kernel.org/linus/3feec909

Comment 2 Eugene Teo (Security Response) 2010-06-23 04:00:16 UTC
Statement:

This issue did not affect the version of Linux kernel as shipped with Red Hat
Enterprise Linux 3, 4, 5 and Red Hat Enterprise MRG as they did not backport the upstream commit ffcebb16 that introduced this vulnerability.

Comment 3 Kyle McMartin 2010-06-23 12:35:29 UTC
Pushed out fixes to F-12/13. Thanks, Eugene.

Comment 4 Fedora Update System 2010-07-08 18:23:13 UTC
kernel-2.6.33.6-147.fc13 has been pushed to the Fedora 13 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2010-07-13 07:48:33 UTC
kernel-2.6.32.16-141.fc12 has been pushed to the Fedora 12 stable repository.  If problems still persist, please make note of it in this bug report.


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