diff --git a/fs/dcache.c b/fs/dcache.c
index f1e801785976..17222fa5bdc6 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2534,6 +2534,8 @@ static int prepend_path(const struct path *path,
 	struct dentry *dentry = path->dentry;
 	struct vfsmount *vfsmnt = path->mnt;
 	struct mount *mnt = real_mount(vfsmnt);
+	char *orig_buffer = *buffer;
+	int orig_len = *buflen;
 	bool slash = false;
 	int error = 0;
 
@@ -2541,6 +2543,14 @@ static int prepend_path(const struct path *path,
 		struct dentry * parent;
 
 		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
+			/* Escaped? */
+			if (dentry != vfsmnt->mnt_root) {
+				*buffer = orig_buffer;
+				*buflen = orig_len;
+				slash = false;
+				error = 3;
+				goto global_root;
+			}
 			/* Global root? */
 			if (!mnt_has_parent(mnt))
 				goto global_root;