Linux Kenrel knfsd denial of service

linux-kernel-knfsd-dos (58957)

Medium Risk

Description:

Linux Kernel is vulnerable to a denial of service, caused by an error related to when the current->mm based modifier to the overcommit goes through a NULL pointer. A local attacker could exploit this vulnerability via an export of export shmemfs objects and runing strict overcommit to cause knfsd to crash.

*CVSS:

Base Score:	1.9
Access Vector:	Local
Access Complexity:	Medium
Authentication:	None
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	Partial
Temporal Score:	1.5
Exploitability:	Unproven
Remediation Level:	Temporary-Fix
Report Confidence:	Confirmed

Consequences:

Denial of Service

Remedy:

Refer to Red Hat Bugzilla Bug 595970 for patch, upgrade or suggested workaround information. See References.

References:

• Red Hat Bugzilla ¿ Bug 595970 : CVE-2010-1643 kernel: nfsd: fix vm overcommit crash.
• BID-40377: Linux Kernel 'knfsd' 'current->mm' Modifier Local Denial of Service Vulnerability
• CVE-2010-1643: mm/shmem.c in the Linux kernel before 2.6.28-rc3, when strict overcommit is enabled, does not properly handle the export of shmemfs objects by knfsd, which allows attackers to cause a denial of service (NULL pointer dereference and knfsd crash) or possibly have unspecified other impact via unknown vectors.
• MDVSA-2010:198: kernel
• RHSA-2010-0631: Important: kernel-rt security and bug fix update
• SUSE-SA:2010:031: Linux kernel security update

Platforms Affected:

• Linux Kernel 2.6.34
• Mandriva Linux 2009.0
• Mandriva Linux 2009.0 X86_64
• RedHat MRG v1 for Red Hat Enterprise Linux 5

Reported:

May 26, 2010

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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