Bug 607054 (CVE-2010-2495)

Summary: CVE-2010-2495 kernel: l2tp: Fix oops in pppol2tp_xmit
Product: [Other] Security Response Reporter: Eugene Teo (Security Response) <eteo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: arozansk, davej, kmcmartin, lwang, pmatouse, rcvalle, tcallawa
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2012-03-28 08:36:36 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 607055    
Bug Blocks:    

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:

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

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- 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- has been pushed to the Fedora 12 stable repository.  If problems still persist, please make note of it in this bug report.