The patch titled Subject: kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time has been added to the -mm tree. Its filename is kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch

This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kasan-prevent-cpu_quarantine-corru... and later at https://ozlabs.org/~akpm/mmotm/broken-out/kasan-prevent-cpu_quarantine-corru...

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------------------------------------------------------ From: Zqiang qiang1.zhang@intel.com Subject: kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/ destroy(). The kasan_quarantine_remove_cache() call is protected by cpuslock in kmem_cache_destroy() to ensure serialization with kasan_cpu_offline().

However the kasan_quarantine_remove_cache() call is not protected by cpuslock in kmem_cache_shrink(). When a CPU is going offline and cache shrink occurs at same time, the cpu_quarantine may be corrupted by interrupt (per_cpu_remove_cache operation).

So add a cpu_quarantine offline flags check in per_cpu_remove_cache().

Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com Signed-off-by: Zqiang qiang1.zhang@intel.com Cc: Andrey Ryabinin ryabinin.a.a@gmail.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Alexander Potapenko glider@google.com Cc: Andrey Konovalov andreyknvl@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

--- a/mm/kasan/quarantine.c~kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time +++ a/mm/kasan/quarantine.c @@ -315,6 +315,8 @@ static void per_cpu_remove_cache(void *a struct qlist_head *q;

q = this_cpu_ptr(&cpu_quarantine); + if (READ_ONCE(q->offline)) + return; qlist_move_cache(q, &to_free, cache); qlist_free_all(&to_free, cache); } _

Patches currently in -mm which might be from qiang1.zhang@intel.com are

irq_work-use-kasan_record_aux_stack_noalloc-record-callstack.patch kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch kasan-fix-sleeping-function-called-from-invalid-context-on-rt-kernel.patch