[PATCH] f2fs: fix null page reference in redirty_blocks

From: Daeho Jeong
Date: Mon Jan 04 2021 - 20:32:17 EST


From: Daeho Jeong <daehojeong@xxxxxxxxxx>

Fixed null page reference when find_lock_page() fails in
redirty_blocks().

Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
Reported-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
---
fs/f2fs/file.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..bf6682a52433 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)

for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
- if (!page)
+ if (!page) {
ret = -ENOENT;
+ continue;
+ }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
--
2.29.2.729.g45daf8777d-goog