The patch titled
Subject: kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time
has been removed from the -mm tree. Its filename was
kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Zqiang <qiang1.zhang@xxxxxxxxx>
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().
[akpm@xxxxxxxxxxxxxxxxxxxx: add comment, per Zqiang]
Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@xxxxxxxxx
Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/quarantine.c | 7 +++++++
1 file changed, 7 insertions(+)
--- 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 +315,13 @@ static void per_cpu_remove_cache(void *a
struct qlist_head *q;
q = this_cpu_ptr(&cpu_quarantine);
+ /*
+ * Ensure the ordering between the writing to q->offline and
+ * per_cpu_remove_cache. Prevent cpu_quarantine from being corrupted
+ * by interrupt.
+ */
+ 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@xxxxxxxxx are
kasan-fix-sleeping-function-called-from-invalid-context-on-rt-kernel.patch
