[PATCH 5.15.y] f2fs: fix dentry folio leak in find_in_level

[Sasha Levin <sashal@kernel.org>]

From: Guanghui Yang <3497809730@qq.com>

[ Upstream commit cca7d3e30bf30333314e31bc70b9a739f1342167 ]

find_in_level() gets a dentry folio with f2fs_find_data_folio() before
calling find_in_block().  If find_in_block() returns an error, the
function stores the error in res_folio and breaks out of the loop without
dropping the dentry folio.

This leaks the folio reference on the find_in_block() error path.  Drop
the dentry folio before returning the error to the caller.

Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
Cc: stable@vger.kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Guanghui Yang <3497809730@qq.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[ Replaced f2fs_folio_put(dentry_folio, false) with f2fs_put_page(dentry_page, 0) for the page-based API. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/dir.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index da717e4d6aee7..8ec23b8af64e1 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -372,6 +372,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 
 		de = find_in_block(dir, dentry_page, fname, &max_slots, use_hash);
 		if (IS_ERR(de)) {
+			f2fs_put_page(dentry_page, 0);
 			*res_page = ERR_CAST(de);
 			de = NULL;
 			break;
-- 
2.53.0