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Bug 411501 - app-emulation/qemu-kvm : "ext4_fill_flex_info()" Denial of Service Vulnerability
Summary: app-emulation/qemu-kvm : "ext4_fill_flex_info()" Denial of Service Vulnerability
Status: RESOLVED INVALID
Alias: None
Product: Gentoo Security
Classification: Unclassified
Component: Vulnerabilities (show other bugs)
Hardware: All Linux
: Normal minor (vote)
Assignee: Gentoo Security
URL: https://secunia.com/advisories/48645/
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-04-10 18:32 UTC by Agostino Sarubbo
Modified: 2012-04-11 14:08 UTC (History)
1 user (show)

See Also:
Package list:
Runtime testing required: ---


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Description Agostino Sarubbo gentoo-dev 2012-04-10 18:32:20 UTC
From secunia security advisory at $URL:


Description
A vulnerability has been reported in KVM qemu-kvm, which can be exploited by malicious, local users in a guest virtual machine to cause a DoS (Denial of Service).

The vulnerability is caused due to an error within the "ext4_fill_flex_info()" function in fs/ext4/super.c when mounting a file system and can be exploited to cause a division by zero.

NOTE: This is caused due to an incomplete fix for vulnerability #2 in:
https://secunia.com/advisories/37658/


Solution:
Fixed in the GIT repository.http://git.kernel.org/?p=virt/kvm/kvm.git;a=commit;h=d50f2ab6f050311dbf7b8f5501b25f0bf64a439b
Comment 1 Doug Goldstein (RETIRED) gentoo-dev 2012-04-10 18:40:31 UTC
This is a kernel bug in the ext4 filesystem kernel module. The patch you referenced is from the KVM repo that is branched off of Linus' tree.
Comment 2 Agostino Sarubbo gentoo-dev 2012-04-10 18:51:42 UTC
(In reply to comment #1)
> This is a kernel bug in the ext4 filesystem kernel module. The patch you
> referenced is from the KVM repo that is branched off of Linus' tree.

I just reported secunia advisory, let me investigate
Comment 3 Agostino Sarubbo gentoo-dev 2012-04-11 14:08:42 UTC
(In reply to comment #1)
> This is a kernel bug in the ext4 filesystem kernel module. The patch you
> referenced is from the KVM repo that is branched off of Linus' tree.

As you said this is completely invalid, I will poke secunia to know what's up.

Apologize for the mailspam.