CVE-2011-2491

Severity: medium (CVSS 4.9 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2013-03-01 · updated 2026-06-16
Weakness: CWE-400

Description

The Network Lock Manager (NLM) protocol implementation in the NFS client functionality in the Linux kernel before 3.0 allows local users to cause a denial of service (system hang) via a LOCK_UN flock system call.

Affected products

Linux kernel: before 3.0 — fixed in 3.0
RedHat Enterprise Linux Desktop: 5.0
RedHat Enterprise Linux Server: 5.0
RedHat Enterprise Linux Workstation: 5.0

How to fix

Upgrade to a fixed version: Linux kernel 3.0. Check the vendor advisory for mitigations.

References

http://ftp.osuosl.org/pub/linux/kernel/v3.0/ChangeLog-3.0
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0b760113a3a155269a3fba93a409c640031dd68f
http://rhn.redhat.com/errata/RHSA-2011-1212.html
http://www.openwall.com/lists/oss-security/2011/06/23/6
https://bugzilla.redhat.com/show_bug.cgi?id=709393
https://github.com/torvalds/linux/commit/0b760113a3a155269a3fba93a409c640031dd68f
http://ftp.osuosl.org/pub/linux/kernel/v3.0/ChangeLog-3.0
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0b760113a3a155269a3fba93a409c640031dd68f
http://rhn.redhat.com/errata/RHSA-2011-1212.html
http://www.openwall.com/lists/oss-security/2011/06/23/6
https://bugzilla.redhat.com/show_bug.cgi?id=709393
https://github.com/torvalds/linux/commit/0b760113a3a155269a3fba93a409c640031dd68f

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