+ kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

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-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch

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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