--- zzzz-none-000/linux-4.4.60/fs/ext4/extents.c	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-1750e-727/linux-4.4.60/fs/ext4/extents.c	2021-02-04 17:41:59.000000000 +0000
@@ -876,6 +876,12 @@
 
 	eh = ext_inode_hdr(inode);
 	depth = ext_depth(inode);
+	if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
+		EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
+				 depth);
+		ret = -EFSCORRUPTED;
+		goto err;
+	}
 
 	if (path) {
 		ext4_ext_drop_refs(path);