CVE-2026-63977 Linux CVE debrief

Who should care

Linux kernel users and maintainers should review and apply the patch to eliminate the race condition. This vulnerability affects Linux kernel deployments, and users should verify their kernel versions and configurations to identify potential exposure. Maintainers and security teams should prioritize patching to prevent potential issues.

Technical summary

The Linux kernel vulnerability CVE-2026-63977 was resolved by replacing change_work with __dpll_device_change_ntf() to send device change notifications without deadlocking on dpll_lock. This change prevents a race condition where change_work could be re-scheduled after cancel_work_sync() during device teardown, potentially causing the handler to dereference a freed or NULL dpll_dev pointer. The affected component is the Linux kernel's dpll: zl3073x. The fix ensures that device change notifications are sent safely without introducing a race condition.

Defensive priority

High priority for Linux kernel maintainers and users to apply the patch and prevent potential issues.

Recommended defensive actions

• Review and apply the Linux kernel patch to eliminate the race condition.
• Monitor Linux kernel updates and apply patches promptly.
• Inventory Linux kernel versions and configurations to identify potential exposure.
• Verify kernel patch deployment in managed environments.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-07-19T16:17:16.860Z and has not been modified since then. The NVD entry is currently Received. The Linux kernel vulnerability CVE-2026-63977 was resolved by replacing change_work with __dpll_device_change_ntf() to send device change notifications without deadlocking on dpll_lock. This change prevents a race condition where change_work could be re-scheduled after cancel_work_sync() during device teardown, potentially causing the handler to dereference a freed or NULL dpll_dev pointer. Evidence is limited to CVE and NVD details.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.