diff --git a/fs/dcache.c b/fs/dcache.c
index 85a2aad..ad13700 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2706,6 +2706,11 @@
 				dput(new);
 				return ERR_PTR(-EIO);
 			}
+			if (d_ancestor(new, dentry)) {
+				spin_unlock(&inode->i_lock);
+				dput(new);
+				return ERR_PTR(-EIO);
+			}
 			write_seqlock(&rename_lock);
 			__d_materialise_dentry(dentry, new);
 			write_sequnlock(&rename_lock);