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From: Ma Ke <make24@iscas.ac.cn>
To: willy@infradead.org, akpm@linux-foundation.org
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Ma Ke <make24@iscas.ac.cn>
Subject: [PATCH] filemap: fix error pointer dereference in filemap_fault()
Date: Tue, 16 Jul 2024 10:25:18 +0800	[thread overview]
Message-ID: <20240716022518.430237-1-make24@iscas.ac.cn> (raw)

This code calls folio_put() on an error pointer which will lead to a
crash.  Check for both error pointers and NULL pointers before calling
folio_put().

Fixes: 38a55db9877c ("filemap: Handle error return from __filemap_get_folio()")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
 mm/filemap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 657bcd887fdb..cd26617d8987 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3420,7 +3420,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
 	 * re-find the vma and come back and find our hopefully still populated
 	 * page.
 	 */
-	if (!IS_ERR(folio))
+	if (!IS_ERR_OR_NULL(folio))
 		folio_put(folio);
 	if (mapping_locked)
 		filemap_invalidate_unlock_shared(mapping);
-- 
2.25.1



             reply	other threads:[~2024-07-16  2:25 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-16  2:25 Ma Ke [this message]
2024-07-16  2:30 ` Matthew Wilcox

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