CVE-2026-64416 Linux CVE debrief

Who should care

System administrators and security teams responsible for managing Linux-based systems, particularly those running kernel versions 6.12, 6.13, 6.19, and 7.1, should be aware of this vulnerability and take steps to mitigate it.

Why it matters

This vulnerability in the Linux kernel can lead to a NULL pointer dereference, potentially causing denial-of-service conditions. System administrators and security teams should be aware of this issue and take steps to mitigate it, particularly for systems running affected kernel versions.

• Denial-of-service conditions due to system crashes or unresponsiveness.
• Potential for attackers to exploit this vulnerability to disrupt system operations.
• Need for system administrators to validate swap entries and ensure proper formatting.
• Importance of keeping Linux kernel versions up-to-date with the latest security patches.

Technical summary

The vulnerability exists in the Linux kernel's handling of swap entries. A corrupted PTE that is incorrectly formatted as a swap entry can cause a NULL pointer dereference in the lookup_swap_cgroup_id function. This function is called by swap_pte_batch, which is used to handle swap entries in the page table. The issue was introduced due to a missing check in the lookup_swap_cgroup_id function. The vulnerability can be triggered by a corrupted PTE that has been incorrectly formatted as a swap entry, leading to a NULL pointer dereference. This can cause the system to crash or become unresponsive, potentially leading to denial-of-service conditions. The vulnerability is particularly concerning because it can be A

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided patches to address the vulnerability.
• Ensure that systems running Linux kernel versions 6.12, 6.13, 6.19, and 7.1 are updated to the latest version.
• Monitor systems for unusual activity or crashes that may indicate exploitation of this vulnerability.
• Validate swap entries and ensure that they are properly formatted to prevent similar issues.
• Perform a thorough review of system logs to detect potential exploitation attempts.
• Consider implementing additional monitoring and detection controls to identify potential threats.
• Verify that all necessary security patches are applied and up-to-date.

Evidence notes

The vulnerability was introduced due to a missing check in the lookup_swap_cgroup_id function, which is called by swap_pte_batch. This function is used to handle swap entries in the page table. The issue was exacerbated by a commit that allowed zap_pte_range to call swap_pte_batch on any non-present, non-none PTE that decodes as a real swap entry, without first validating it against swap_info[].

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.