A race condition exists in the Linux perf subsystem between the functions perf_event_exit_task() and perf_pending_task() during the begin_new_exec() phase of a process transition. When perf_event_exit_task() is invoked, the PF_EXITING flag has not yet been set on the task. As a result, perf_sigtrap() continues to execute and may trigger WARN_ON_ONCE if the event’s context task differs from the current task. When both functions run concurrently, the context task can become TASK_TOMBSTONE, causing repeated warnings that can culminate in a kernel panic. The flaw therefore leads to system unavailability through a kernel crash rather than exposing a direct code‑execution path.

Every Linux kernel build that does not contain the fix introduced by the commit series referenced in the CVE is affected. This includes kernels distributed by all major Linux distributions—Ubuntu, Debian, RHEL, CentOS, Fedora, SUSE, and others—prior to the inclusion of the patch. Systems whose kernel packages have not been updated to include the commit are susceptible.

Risk and exploitability: The CVSS score of 4.7 indicates moderate severity, and the EPSS score of <1% reflects a very low likelihood of exploitation. The flaw is not listed in the CISA KEV catalog. Exploitation requires an attacker to operate within a perf context during the brief transition between task exit and exec, which typically implies local or privileged access. Triggering the race can induce a kernel crash, resulting in a denial of service.