From: Daeho Jeong daehojeong@google.com
[ Upstream commit df0736d70c4fa6ed711ba103b61880fe72bb4777 ]
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: Daeho Jeong daehojeong@google.com Reported-by: Colin Ian King colin.king@canonical.com Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") Reviewed-by: Colin Ian King colin.king@canonical.com Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index f585545277d77..cd62b0d3369ab 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4043,8 +4043,10 @@ 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);