From: Wan Jiabing <wanjiabing@vivo.com>
To: Andrew Morton <akpm@linux-foundation.org>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Vlastimil Babka <vbabka@suse.cz>,
David Howells <dhowells@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Wan Jiabing <wanjiabing@vivo.com>
Subject: [PATCH] mm/filemap: Fix NULL pointer dereference in pagecache_get_page
Date: Tue, 26 Apr 2022 16:25:48 +0800 [thread overview]
Message-ID: <20220426082549.590899-1-wanjiabing@vivo.com> (raw)
Fix following coccicheck error:
mm/folio-compat.c:128:17-21: ERROR: folio is NULL but dereferenced.
'folio' would be NULL when getting a reference to a folio failed.
Add a NULL check before dereferring 'folio'.
Fixes: 3f0c6a07fee6 ("mm/filemap: Add filemap_get_folio")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
---
mm/folio-compat.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 46fa179e32fb..54b17c1246c4 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -124,7 +124,9 @@ 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))
+ if (!folio)
+ return NULL;
+ if ((fgp_flags & FGP_HEAD) || xa_is_value(folio))
return &folio->page;
return folio_file_page(folio, index);
}
--
2.35.3
next reply other threads:[~2022-04-26 8:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-26 8:25 Wan Jiabing [this message]
2022-04-26 12:08 ` [PATCH] mm/filemap: Fix NULL pointer dereference in pagecache_get_page Matthew Wilcox
2022-04-26 21:06 ` Andrew Morton
2022-04-26 21:17 ` Matthew Wilcox
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