CVE-2026-89589 Linux CVE debrief

Who should care

Linux kernel maintainers and users, especially those using CXL CPER work, should assess exposure and prioritize verification of affected systems. This includes operators managing Linux kernel deployments, platform administrators, vulnerability management teams, and security teams responsible for ensuring the security and integrity of Linux kernel-based systems.

Why it matters

Linux kernel maintainers and users should assess exposure and prioritize verification of affected systems, especially those using CXL CPER work. The vulnerability can lead to deadlocks, and remediation involves updating to the patched Linux kernel version.

• Potential deadlock in CXL CPER work
• Required verification of affected systems
• Remediation involves updating to patched Linux kernel version

Technical summary

The Linux kernel vulnerability involves the use of raw_spinlock_t for CXL CPER work locks to prevent deadlocks. The CXL CPER work registration and unregistration helpers acquire locks with a spinlock guard, leaving local interrupts enabled, while the post paths execute in hard IRQ context and acquire the same locks with an irqsave guard. This can lead to a deadlock if a CPU holds one of these locks via a spinlock guard when a GHES interrupt arrives on the same CPU.

Defensive priority

Linux kernel maintainers and users should assess exposure and prioritize verification of affected systems, especially those using CXL CPER work. Remediation involves updating to the patched Linux kernel version.

Recommended defensive actions

• Review Linux kernel versions and assess exposure
• Verify CXL CPER work usage and configuration
• Update to patched Linux kernel version if necessary
• 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 Linux kernel vulnerability and its resolution. The NVD entry is currently Received. To verify affected systems, defenders should review Linux kernel versions, assess exposure, and update to patched versions if necessary. The vulnerability involves the use of raw_spinlock_t for CXL CPER work locks to prevent deadlocks. The CXL CPER work registration and unregistration helpers acquire locks with a spinlock guard, leaving local interrupts enabled, while the post paths execute in

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.