CVE-2026-74513 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux-based systems should assess their exposure to this vulnerability and apply patches as needed.

Why it matters

The Linux kernel's dibs module is vulnerable to a use-after-free error, which could potentially allow an attacker to execute arbitrary code or cause a denial-of-service condition. Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux-based systems should assess their exposure to this vulnerability and apply patches as needed.

• Potential code execution or denial-of-service conditions
• Exposure of sensitive data or system compromise
• Elevation of privileges or unauthorized access
• Disruption of critical system services

Technical summary

The Linux kernel's dibs module is vulnerable to a use-after-free error. The dibs_lo_attach_dmb(), dibs_lo_detach_dmb(), and dibs_lo_unregister_dmb() functions are affected. An attacker could potentially exploit this vulnerability to execute arbitrary code or cause a denial-of-service condition. The vulnerability is caused by a use-after-free error in the dibs module, where the dibs_lo_attach_dmb(), dibs_lo_detach_dmb(), and dibs_lo_unregister_dmb() functions look up the dmb_node under dmb_ht_lock, drop the lock, and then operate on the node's refcount. However, nothing keeps the node alive across this window, allowing a concurrent final put to free the node between the lookup and the refcount operation. This

Defensive priority

High

Recommended defensive actions

• Review and apply the provided patches to fix the use-after-free vulnerability in the Linux kernel's dibs module.
• Ensure that the Linux kernel is updated to a version that includes the fix.
• Monitor the Linux kernel's vulnerability status and apply patches as needed.
• 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 vulnerability is caused by a use-after-free error in the dibs module. The dibs_lo_attach_dmb(), dibs_lo_detach_dmb(), and dibs_lo_unregister_dmb() functions look up the dmb_node under dmb_ht_lock, drop the lock, and then operate on the node's refcount. However, nothing keeps the node alive across this window, allowing a concurrent final put to free the node between the lookup and the refcount operation.

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.