Commit 90d2c51d authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: add NULL check for do_walk_down() 



btrfs_find_create_tree_block() may return NULL, so we must check the returned
value, or we will access a NULL pointer.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 2f3014fc

fs/btrfs/extent-tree.c

+4 −1
Original line number Diff line number Diff line
@@ -5205,6 +5205,8 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
	next = btrfs_find_tree_block(root, bytenr, blocksize);

	if (!next) {

		next = btrfs_find_create_tree_block(root, bytenr, blocksize);

		if (!next)

			return -ENOMEM;

		reada = 1;

	}

	btrfs_tree_lock(next);
@@ -5417,7 +5419,8 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans, 
		if (ret > 0) {

			path->slots[level]++;

			continue;

		}

		} else if (ret < 0)

			return ret;

		level = wc->level;

	}

	return 0;