Commit df0736d7 authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: fix null page reference in redirty_blocks 



By Colin's static analysis, we found out there is a null page reference
under low memory situation in redirty_blocks. I've made the page finding
loop stop immediately and return an error not to cause further memory
pressure when we run into a failure to find a page under low memory
condition.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Reported-by: default avatarColin Ian King <colin.king@canonical.com>
Fixes: 5fdb322f ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
Reviewed-by: default avatarColin Ian King <colin.king@canonical.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 7f59b277

fs/f2fs/file.c

+4 −2
Original line number Diff line number Diff line
@@ -4057,8 +4057,10 @@ 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)

			ret = -ENOENT;

		if (!page) {

			ret = -ENOMEM;

			break;

		}

		set_page_dirty(page);

		f2fs_put_page(page, 1);

		f2fs_put_page(page, 0);