diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 4edcbe9..84d7ca1 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -682,6 +682,8 @@
 			if (!cur) {
 				cur = read_tree_block(root, blocknr,
 							 blocksize, gen);
+				if (!cur)
+					return -EIO;
 			} else if (!uptodate) {
 				btrfs_read_buffer(cur, gen);
 			}
@@ -4087,6 +4089,7 @@
 		}
 		btrfs_set_path_blocking(path);
 		cur = read_node_slot(root, cur, slot);
+		BUG_ON(!cur);
 
 		btrfs_tree_lock(cur);