Linux Kernel Vulnerability in Tracing Mechanism Affects Multiple Versions

CVE-2026-99237

What is CVE-2026-99237?

A vulnerability in the Linux kernel's tracing functionality allows for improper locking during certain operations. Specifically, the update_last_data_if_empty() function can be executed with O_TRUNC in a way that two readers might simultaneously access the LAST_BOOT test. This can lead to freeing the module_delta multiple times, particularly if a notifier attempts to update module_delta while it's being freed. The issue arises because the trace_types_lock is not consistently held during these critical operations, resulting in potential system instability or unexpected behavior.

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