Description
In the Linux kernel, the following vulnerability has been resolved:

drm/vc4: Shut down BO cache timer before teardown

The BO cache timer callback schedules time_work, and time_work can rearm
the timer through vc4_bo_cache_free_old().

vc4_bo_cache_destroy() deletes the timer and then cancels the work, which
does not break that cycle: the work being cancelled can rearm the timer,
and the timer then queues work again after teardown.

Use timer_shutdown_sync() instead, so the timer cannot be rearmed and the
cycle ends with cancel_work_sync().
Published: 2026-08-10
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability involves the VC4 buffer object cache timer in the Linux kernel. During teardown, the timer is deleted but the queued work can still rearm it, allowing the timer to continue firing after the cache has been destroyed. This race between timer deletion and work cancellation can lead to a loop that may exhaust kernel resources or trigger a crash. The flaw arises from improper synchronization between timer shutdown and workqueue cancellation.

Affected Systems

The issue appears in the Linux kernel's VC4 DRM driver. No specific version numbers are listed; any kernel that includes the buggy logic before the patch may be affected. The vendor is Linux; product is the Linux kernel itself.

Risk and Exploitability

The CVSS score is not specified and EPSS is not available, so the public data does not quantify risk. The vulnerability is not in CISA KEV but it can be triggered by a process with kernel code execution privileges, making it a local‑only threat. Because the flaw only manifests under specific timing conditions, it is unlikely to be widely exploitable without prior privileged access. Nonetheless, the potential for a kernel crash makes it a moderate risk for impacted systems.

Generated by OpenCVE AI on August 10, 2026 at 14:54 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the latest Linux kernel update that incorporates the commit which replaces timer_shutdown_sync with cancel_work_sync to prevent the timer from being rearmed after cache destruction.
  • If an immediate kernel upgrade is infeasible, consider manually applying the upstream patch from the referenced commits to replace the buggy logic with the corrected synchronization code.
  • Monitor kernel logs for warnings or errors related to VC4 BO cache timer activity and ensure that any custom drivers using the VC4 DRM interface are also updated to the patched version.

Generated by OpenCVE AI on August 10, 2026 at 14:54 UTC.

Tracking

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Advisories

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History

Mon, 10 Aug 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-667

Mon, 10 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Shut down BO cache timer before teardown The BO cache timer callback schedules time_work, and time_work can rearm the timer through vc4_bo_cache_free_old(). vc4_bo_cache_destroy() deletes the timer and then cancels the work, which does not break that cycle: the work being cancelled can rearm the timer, and the timer then queues work again after teardown. Use timer_shutdown_sync() instead, so the timer cannot be rearmed and the cycle ends with cancel_work_sync().
Title drm/vc4: Shut down BO cache timer before teardown
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-10T12:00:57.580Z

Reserved: 2026-07-30T09:28:09.376Z

Link: CVE-2026-68233

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-10T19:00:04Z

Weaknesses