CVE-2026-97937 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, as well as system administrators responsible for managing Linux-based systems, should be aware of this vulnerability and take steps to address it. This vulnerability may be particularly relevant for systems that use the Linux kernel's function graph tracing feature.

Why it matters

This vulnerability has a high CVSS score of 7.8 and is classified as HIGH severity. It requires local access and low privileges to exploit, making it a significant concern for Linux kernel developers and maintainers, as well as system administrators responsible for managing Linux-based systems.

• Potential system crashes or instability due to use-after-free errors.
• Possible elevation of privileges or unauthorized access to sensitive data.
• Increased risk of denial-of-service (DoS) attacks or system compromise.

Technical summary

The Linux kernel's function graph state management is vulnerable to a use-after-free error during fork operations. The `dup_task_struct` function copies the parent's task structure, including the return stack, before `ftrace_graph_init_task` can clear the copied function graph state. If memory allocation fails for `copy_exec_state`, the child process may carry the parent's return stack pointer, leading to a use-after-free error when the parent accesses the freed memory. The issue is resolved by initializing the child function graph state immediately after `dup_task_struct`, before the first fallible operation.

Defensive priority

High

Recommended defensive actions

• Review and apply the provided kernel patches to ensure the vulnerability is addressed.
• Monitor system logs for potential use-after-free errors related to the function graph state.
• Consider implementing additional memory safety mechanisms, such as address space layout randomization (ASLR) and data execution prevention (DEP).
• 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 was reported via KASAN, which detected a slab-use-after-free error in the `function_graph_enter_regs` function. The issue is resolved by initializing the child function graph state immediately after `dup_task_struct`, before the first fallible 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.