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Fencer Intel
medium 4.9

CVE-2011-4622 json

The create_pit_timer function in arch/x86/kvm/i8254.c in KVM 83, and possibly other versions, does not properly handle when Programmable In…

published 2012-01-27 14 y ago modified 2026-06-16 4 mo ago also EUVD-2011-4545

cvss
4.9
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

The create_pit_timer function in arch/x86/kvm/i8254.c in KVM 83, and possibly other versions, does not properly handle when Programmable Interval Timer (PIT) interrupt requests (IRQs) when a virtual interrupt controller (irqchip) is not available, which allows local users to cause a denial of service (NULL pointer dereference) by starting a timer.

Patch / fix

  • kernel RHEL 6 2.6.32-220.7.1.el6
  • perf RHEL 6 2.6.32-220.7.1.el6
  • python-perf RHEL 6 2.6.32-220.7.1.el6
  • kernel-kdump RHEL 6 2.6.32-220.7.1.el6
  • kernel-firmware RHEL 6 2.6.32-220.7.1.el6
  • kernel-bootwrapper RHEL 6 2.6.32-220.7.1.el6
  • kernel-debuginfo-common-i686 RHEL 6 2.6.32-220.7.1.el6
  • kernel-debuginfo-common-ppc64 RHEL 6 2.6.32-220.7.1.el6

red hat advisories RHSA-2012:0350RHSA-2012:0051

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-4622 updated cvss 4.9

kernel: kvm: pit timer with no irqchip crashes the system

  • Red Hat Enterprise Linux 5 kvm
    affected: no fix available
  • Red Hat Enterprise Linux Desktop (v. 6) perf 2.6.32-220.7.1.el6, kernel 2.6.32-220.7.1.el6, kernel-firmware 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6 Red Hat Enterprise Linux Desktop Optional (v. 6) kernel 2.6.32-220.7.1.el6, python-perf 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6 Red Hat Enterprise Linux HPC Node (v. 6) perf 2.6.32-220.7.1.el6, kernel 2.6.32-220.7.1.el6, kernel-firmware 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6 Red Hat Enterprise Linux HPC Node Optional (v. 6) kernel 2.6.32-220.7.1.el6, python-perf 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6 Red Hat Enterprise Linux Server (v. 6) perf 2.6.32-220.7.1.el6, kernel 2.6.32-220.7.1.el6, kernel-kdump 2.6.32-220.7.1.el6, kernel-firmware 2.6.32-220.7.1.el6, kernel-bootwrapper 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, +3 more Red Hat Enterprise Linux Server Optional (v. 6) kernel 2.6.32-220.7.1.el6, python-perf 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, kernel-debuginfo-common-ppc64 2.6.32-220.7.1.el6, kernel-debuginfo-common-s390x 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 6) perf 2.6.32-220.7.1.el6, kernel 2.6.32-220.7.1.el6, kernel-firmware 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6 Red Hat Enterprise Linux Workstation Optional (v. 6) kernel 2.6.32-220.7.1.el6, python-perf 2.6.32-220.7.1.el6, kernel-debuginfo-common-i686 2.6.32-220.7.1.el6, kernel-debuginfo-common-x86_64 2.6.32-220.7.1.el6
    fixed: vendor fix RHSA-2012:0350
  • Red Hat RHEL Desktop Multi OS (v. 5 client) kvm 83-239.el5_7.1, kmod-kvm 83-239.el5_7.1, kvm-tools 83-239.el5_7.1, kvm-qemu-img 83-239.el5_7.1 Red Hat RHEL Virtualization (v. 5 server) kvm 83-239.el5_7.1, kmod-kvm 83-239.el5_7.1, kvm-tools 83-239.el5_7.1, kvm-qemu-img 83-239.el5_7.1
    fixed: vendor fix RHSA-2012:0051
  • Red Hat Enterprise Linux 4 kernel Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:N/I:N/A:C

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.