mm, slub: fix mismatch between reconstructed freelist depth and cnt

stable inclusion
from linux-4.19.214
commit 21e23e4c02fc9aa1f4b037f30e47d215d1a27f21

--------------------------------

commit 899447f6 upstream.

If object's reuse is delayed, it will be excluded from the reconstructed
freelist.  But we forgot to adjust the cnt accordingly.  So there will
be a mismatch between reconstructed freelist depth and cnt.  This will
lead to free_debug_processing() complaining about freelist count or a
incorrect slub inuse count.

Link: https://lkml.kernel.org/r/20210916123920.48704-3-linmiaohe@huawei.com


Fixes: c3895391 ("kasan, slub: fix handling of kasan_slab_free hook")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>