CVE intelligence and bounded remediation

CVE-2025-71104 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Fix VM hard lockup after prolonged inactivity with periodic HV timer When advancing the target expiration for the guest's APIC timer in periodic mode, set the expiration to "now" if the target expiration is in the past (similar to what is done in update_target_expiration()). Blindly adding the period to the previous target expiration can result in KVM generating a practically unbounded number of hrtimer IRQs due to programming an expired timer over and over. In extreme scenarios, e.g. if userspace pauses/suspends a VM for an extended duration, this can even cause hard lockups in the host. Currently, the bug only affects Intel CPUs when using the hypervisor timer (HV timer), a.k.a. the VMX preemption timer. Unlike the software timer, a.k.a. hrtimer, which KVM keeps running even on exits to userspace, the HV timer only runs while the guest is active. As a result, if the vCPU does not run for an extended duration, there will be a huge gap between the target expiration and the current time the vCPU resumes running. Because the target expiration is incremented by only one period on each timer expiration, this…

Severity
Medium
CVSS
5.5 (3.1)
Published
2026-01-14
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-667

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 4.17
  • linux / linux_kernel / 6.19

Showing 3 representative product identities from 17 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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