Description
In the Linux kernel, the following vulnerability has been resolved: perf/aux: Fix page UAF in map_range() map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are serialized by rb->aux_mutex, and mmap_mutex is per event. Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows: CPU 0 CPU 1 ===== ===== rb_alloc_aux() map_range() [1]: allocate rb->aux_pages[0] [2]: rb->aux_nr_pages++ [3]: perf_mmap_to_page() returns rb->aux_pages[0] [4]: map it as VM_PFNMAP [5]: rb->aux_pgoff = 1 munmap the page [6]: free rb->aux_pages[0] Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a mapping to a freed physical frame. Fix this by taking rb->aux_mutex across the page walk in map_range().
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
b709eb872e19a19607bbb6d2975bc264d59735cf to < c8b7e113f7b61eef2f017e6329c27c2331058c5aaffectedb709eb872e19a19607bbb6d2975bc264d59735cf to < 0cff05bd2186020f8706233e261016d149cc24dbaffectedb709eb872e19a19607bbb6d2975bc264d59735cf to < 5948aaf64f81f217a25dcc2bf6c0779bca19566caffected
Linux Linux
Default version status: affected
6.14affected0 to < 6.14unaffected6.18.39 to ≤ 6.18.*unaffected7.1.4 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected