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Bug 984664 (CVE-2013-4125)

Summary: CVE-2013-4125 kernel: ipv6: BUG_ON in fib6_add_rt2node()
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: agordeev, anton, bhu, davej, dhoward, esammons, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, jkurik, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, matt, mcressma, npajkovs, plougher, rt-maint, rvrbovsk, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,public=20130715,reported=20130712,source=vendor-sec,cvss2=7.1/AV:N/AC:M/Au:N/C:N/I:N/A:C,rhel-5/kernel=notaffected,rhel-6/kernel=notaffected,rhel-7/kernel=affected,mrg-2/realtime-kernel=affected,fedora-all/kernel=affected
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-07-15 12:19:28 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Bug Depends On: 984667, 984668    
Bug Blocks: 984673    

Description Petr Matousek 2013-07-15 12:16:51 EDT
If two router advertisment speaker announce seperate default gateways with infinite timeout the kernel currently packs these routes together into an ecmp route set. If one of the RA speaker now changes the advertised expiration to a lower value and a third route with infinite timeout pops up we end up with a BUG_ON.

Remote attacker could use this flaw to crash the system.

Fixed by:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=307f2fb95e9b96b3577916e73d92e104f8f26494

Introduced by:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=51ebd3181572af8d5076808dab2682d800f6da5d

Introduced in upstream version:
v3.7-rc1

Acknowledgements:

Red Hat would like to thank Hannes Frederic Sowa for reporting this issue.
Comment 1 Petr Matousek 2013-07-15 12:19:28 EDT
Statement:

Not vulnerable.

This issue did not affect the kernel packages as shipped with Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2.
Comment 3 Petr Matousek 2013-07-15 12:26:04 EDT
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 984668]