Messages in this thread Patch in this message | | | From | cgel.zte@gmail ... | Subject | [PATCH linux-next] mm/folio-compat: fix potential NULL pointer access | Date | Mon, 13 Sep 2021 08:11:13 +0000 |
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From: xu xin <xu.xin16@zte.com.cn>
The pointer 'folio' might be NULL, but the structure it points to is accessed. Accordingly, we add a check of NULL pointer by 'if (!folio)'. Secondly, there is no need to check if folio is pointer or value with 'xa_is_value(folio)' because folio is alwayse pointer.
Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: xu xin <xu.xin16@zte.com.cn> --- 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 5b6ae1da314e..a1b60310c7ba 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -123,7 +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)) + if (!folio) + return NULL; + if ((fgp_flags & FGP_HEAD)) return &folio->page; return folio_file_page(folio, index); } -- 2.25.1
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