CVE-2026-89791

In the Linux kernel, the following vulnerability has been resolved: perf: Fix use-after-free when perf mmap revival races with the last munmap perfmmapclose drops rb-mmapcount without holding event-mmapmutex the refcountdecandtest right before the refcountdecandmutexlock of event-mmapcount. A...

CVE-2026-89791

CVE-2026-89791 is a use-after-free race condition in the Linux kernel's perf subsystem . The root cause is that perf_mmap_close() drops rb->mmap_count without holding event->mmap_mutex, allowing a concurrent perf_mmap_rb() revival path to free a newly allocated ring buffer that another proc...