* FAILED: patch "[PATCH] kasan: prevent cpu_quarantine corruption when CPU offline and" failed to apply to 4.9-stable tree
@ 2022-05-02 17:36 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2022-05-02 17:36 UTC (permalink / raw)
To: qiang1.zhang, akpm, andreyknvl, dvyukov, glider, ryabinin.a.a,
stable, torvalds
Cc: stable
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 31fa985b4196f8a66f027672e9bf2b81fea0417c Mon Sep 17 00:00:00 2001
From: Zqiang <qiang1.zhang@intel.com>
Date: Wed, 27 Apr 2022 12:41:56 -0700
Subject: [PATCH] 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@linux-foundation.org: add comment, per Zqiang]
Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 08291ed33e93..0a9def8ce5e8 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -315,6 +315,13 @@ static void per_cpu_remove_cache(void *arg)
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);
}
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2022-05-02 17:36 FAILED: patch "[PATCH] kasan: prevent cpu_quarantine corruption when CPU offline and" failed to apply to 4.9-stable tree gregkh
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