mm/damon/paddr: fix folio_size() call after folio_put() in damon_pa_young()

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: 397b0c3 ("mm/damon/paddr: remove folio_sz field from damon_pa_access_chk_result")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <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>

Author: sjp38

mm/damon/paddr.c

@@ -130,7 +130,6 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
 			accessed = false;
 		else
 			accessed = true;
-		folio_put(folio);
 		goto out;
 	}
 
@@ -144,10 +143,10 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
 
 	if (need_lock)
 		folio_unlock(folio);
-	folio_put(folio);
 
 out:
 	*folio_sz = folio_size(folio);
+	folio_put(folio);
 	return accessed;
 }