CVE-2026-98765 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux kernel-based systems using the dummy-hcd driver should assess exposure and verify the patch application.

Why it matters

The vulnerability in the Linux kernel's dummy-hcd driver could lead to issues with gadget driver unbind routines if not properly patched. Linux kernel developers, maintainers, and users of affected systems should verify and apply the patch.

• Verify patch application to prevent potential gadget driver issues
• Assess exposure and prioritize patching for Linux kernel-based systems using dummy-hcd

Technical summary

The Linux kernel's dummy-hcd driver did not properly increment the callback_usage counter during request completion callbacks. This oversight could lead to gadget driver unbind routines running before all outstanding request completions have finished. The fix involves incrementing the callback_usage value across request completion callbacks to ensure proper synchronization of request completions in the dummy-hcd driver. This change ensures that the gadget driver's unbind routine does not run prematurely, preventing potential issues with Linux kernel-based systems using the dummy-hcd driver.

Defensive priority

Verify and apply the patch to ensure proper synchronization of request completions in the dummy-hcd driver.

Recommended defensive actions

• Verify the Linux kernel version and check if the patch is applied
• Review and update the dummy-hcd driver configuration
• Monitor system logs for potential issues with gadget drivers
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source references provide details on the vulnerability and its fix in the Linux kernel. The dummy-hcd driver's improper synchronization of request completions could lead to issues with gadget driver unbind routines. The fix involves incrementing the callback_usage value across request completion callbacks to ensure proper synchronization.

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.