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From: Yi Wang <wang.yi59@zte.com.cn>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	xue.zhihong@zte.com.cn, wang.yi59@zte.com.cn,
	jiang.xuexin@zte.com.cn, zealci@zte.com.cn,
	Changcheng Deng <deng.changcheng@zte.com.cn>
Subject: [PATCH linux-next] mm/folio-compat.c: folio should not be NULL when it is referenced
Date: Mon, 23 Aug 2021 08:47:35 +0800	[thread overview]
Message-ID: <20210823004735.32013-1-wang.yi59@zte.com.cn> (raw)


[-- Attachment #1.1: Type: text/plain, Size: 996 bytes --]

From: Changcheng Deng <deng.changcheng@zte.com.cn>

A bug was found by coccinelle:
folio is NULL but dereferenced
Therefore,added a check to make sure 'folio' is not NULL.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
---
 mm/folio-compat.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 5b6ae1d..bee45e7 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -123,8 +123,9 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
 	struct folio *folio;
 
 	folio = __filemap_get_folio(mapping, index, fgp_flags, gfp);
-	if ((fgp_flags & FGP_HEAD) || !folio || xa_is_value(folio))
-		return &folio->page;
+	if ((fgp_flags & FGP_HEAD) || xa_is_value(folio))
+		if (folio != NULL)
+			return &folio->page;
 	return folio_file_page(folio, index);
 }
 EXPORT_SYMBOL(pagecache_get_page);
-- 
1.8.3.1

             reply	other threads:[~2021-08-23  0:48 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-23  0:47 Yi Wang [this message]
2021-08-23  1:05 ` [PATCH linux-next] mm/folio-compat.c: folio should not be NULL when it is referenced Matthew Wilcox

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