CVE-2024-56706

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> s390/cpum_sf: Fix and protect memory allocation of SDBs with mutex<br /> <br /> Reservation of the PMU hardware is done at first event creation<br /> and is protected by a pair of mutex_lock() and mutex_unlock().<br /> After reservation of the PMU hardware the memory<br /> required for the PMUs the event is to be installed on is<br /> allocated by allocate_buffers() and alloc_sampling_buffer().<br /> This done outside of the mutex protection.<br /> Without mutex protection two or more concurrent invocations of<br /> perf_event_init() may run in parallel.<br /> This can lead to allocation of Sample Data Blocks (SDBs)<br /> multiple times for the same PMU.<br /> Prevent this and protect memory allocation of SDBs by<br /> mutex.