CVE-2026-97923 Linux CVE debrief

Who should care

Linux kernel maintainers, Linux distribution maintainers, and users of Linux kernel tracing subsystem should assess exposure and verify patch deployment to prevent potential exploitation attempts. They should also monitor Linux kernel tracing subsystem logs for suspicious activity and review compensating controls for exposed systems.

Why it matters

A vulnerability in the Linux kernel's tracing subsystem has been resolved. Linux kernel maintainers and users should assess exposure and verify patch deployment to prevent potential exploitation attempts.

• Verify patch deployment to prevent potential exploitation attempts
• Monitor Linux kernel tracing subsystem logs for suspicious activity

Technical summary

The create_var_ref function in the Linux kernel's tracing subsystem allocates a VAR_REF hist_field and then calls init_var_ref to fill it in. When init_var_ref fails, the field is leaked. This issue has been addressed by calling __destroy_hist_field to free the field when initialization fails. The vulnerability was resolved through a patch that modifies the create_var_ref function to properly handle the allocation and deallocation of the VAR_REF hist_field. The patch ensures that the field is freed when initialization fails, preventing a memory leak.

Defensive priority

Linux kernel maintainers and users should assess exposure and verify patch deployment.

Recommended defensive actions

• Assess exposure of Linux kernel deployments to this vulnerability
• Verify patch deployment for affected Linux kernel versions
• Monitor Linux kernel tracing subsystem logs for potential exploitation attempts
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Four source references from the Linux kernel Git repository are provided. The vulnerability was introduced in the Linux kernel's tracing subsystem, which is used for tracing and debugging purposes. The create_var_ref function is used to allocate a VAR_REF hist_field, which is then used to store information about the variable reference. When the init_var_ref function fails to initialize the VAR_REF hist_field, the field is leaked, resulting in a memory leak. The patch

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.