CVE-2011-2521

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: 2012-05-24 · updated 2026-06-16
Weakness: CWE-189

Description

The x86_assign_hw_event function in arch/x86/kernel/cpu/perf_event.c in the Performance Events subsystem in the Linux kernel before 2.6.39 does not properly calculate counter values, which allows local users to cause a denial of service (panic) via the perf program.

Affected products

Linux kernel: before 2.6.39 — fixed in 2.6.39

How to fix

Upgrade to a fixed version: Linux kernel 2.6.39. Check the vendor advisory for mitigations.

References

http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=fc66c5210ec2539e800e87d7b3a985323c7be96e
http://www.openwall.com/lists/oss-security/2011/07/06/4
https://bugzilla.redhat.com/show_bug.cgi?id=719228
https://github.com/torvalds/linux/commit/fc66c5210ec2539e800e87d7b3a985323c7be96e
http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=fc66c5210ec2539e800e87d7b3a985323c7be96e
http://www.openwall.com/lists/oss-security/2011/07/06/4
https://bugzilla.redhat.com/show_bug.cgi?id=719228
https://github.com/torvalds/linux/commit/fc66c5210ec2539e800e87d7b3a985323c7be96e

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