CVE-2026-23271: Concurrent Execution using Shared Resource with Improper Synchronization

In the Linux kernel, the following vulnerability has been resolved:

perf: Fix __perf_event_overflow() vs perf_remove_from_context() race

Make sure that __perf_event_overflow() runs with IRQs disabled for all possible callchains. Specifically the software events can end up running it with only preemption disabled.

This opens up a race vs perf_event_exit_event() and friends that will go and free various things the overflow path expects to be present, like the BPF program.