CVE-2026-89452 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, as well as system administrators responsible for kernel updates and vulnerability management, should review and apply the kernel patch to ensure the vulnerability is resolved. They should also verify the IOMMU configuration and sysfs device registration, and monitor system logs for potential issues related to the IOMMU object. Additionally, they should assess their system's exposure to this vulnerability and plan to

Why it matters

A Linux kernel vulnerability has been resolved, involving the msm_iommu_probe() function. The issue arises when the function adds its devm-managed IOMMU object to qcom_iommu_devices before adding the IOMMU sysfs device and registering it with the IOMMU core. If iommu_device_sysfs_add() or iommu_device_register() fails, the probe returns with the object still on qcom_iommu_devices, potentially leaving a dangling list entry. Linux kernel developers and maintainers, as well as system administrators responsible for kernel updates and vulnerability management, should review and apply the kernel patch to ensure the vulnerability is resolved.

• Verification of IOMMU configuration and sysfs device registration is required to ensure the vulnerability is resolved.
• Potential for dangling list entries if probe returns with object still on qcom_iommu_devices.
• Monitoring system logs for potential issues related to the IOMMU object is necessary.

Technical summary

The msm_iommu_probe() function adds its devm-managed IOMMU object to qcom_iommu_devices before adding the IOMMU sysfs device and registering it with the IOMMU core. If iommu_device_sysfs_add() or iommu_device_register() fails, the probe returns with the object still on qcom_iommu_devices, potentially leaving a dangling list entry. This issue can lead to unexpected behavior or crashes if the dangling list entry is accessed or manipulated. Linux kernel developers and maintainers should review the code changes and apply the patch to prevent such issues.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the kernel patch to ensure the vulnerability is resolved.
• Verify the IOMMU configuration and sysfs device registration.
• Monitor system logs for potential issues related to the IOMMU object.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• 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.

Evidence notes

The CVE record and source item provide details about the Linux kernel vulnerability and its resolution. However, the information available is limited, and further verification is required to determine the full scope of the issue.

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.