+ mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young.patch added to mm-hotfixes-unstable branch

+ mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/paddr: fix folio_size() call after folio_put() in damon_pa_young()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/paddr: fix folio_size() call after folio_put() in damon_pa_young()
Date: Sat, 4 Mar 2023 19:39:48 +0000

Patch series "mm/damon/paddr: Fix folio-use-after-put bugs".

There are two folio accesses after folio_put() in mm/damon/paddr.c file. 
Fix those.


This patch (of 2):

damon_pa_young() is accessing a folio via folio_size() after folio_put()
for the folio has invoked.  Fix it.

Link: https://lkml.kernel.org/r/20230304193949.296391-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230304193949.296391-2-sj@kernel.org
Fixes: 397b0c3a584b ("mm/damon/paddr: remove folio_sz field from damon_pa_access_chk_result")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: <stable@vger.kernel.org>	[6.2.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/damon/paddr.c~mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young
+++ a/mm/damon/paddr.c
@@ -130,7 +130,6 @@ static bool damon_pa_young(unsigned long
 			accessed = false;
 		else
 			accessed = true;
-		folio_put(folio);
 		goto out;
 	}
 
@@ -144,10 +143,10 @@ static bool damon_pa_young(unsigned long
 
 	if (need_lock)
 		folio_unlock(folio);
-	folio_put(folio);
 
 out:
 	*folio_sz = folio_size(folio);
+	folio_put(folio);
 	return accessed;
 }
 
_

Patches currently in -mm which might be from sj@kernel.org are

mm-damon-paddr-fix-folio_size-call-after-folio_put-in-damon_pa_young.patch
mm-damon-paddr-fix-folio_nr_pages-after-folio_put-in-damon_pa_mark_accessed_or_deactivate.patch