--- x/fs/overlayfs/file.c
+++ y/fs/overlayfs/file.c
@@ -204,6 +204,7 @@ static loff_t ovl_llseek(struct file *fi
 	if (ret)
 		return ret;
 
+	inode_lock(inode);
 	/*
 	 * Overlay file f_pos is the master copy that is preserved
 	 * through copy up and modified on read/write, but only real
@@ -220,6 +221,7 @@ static loff_t ovl_llseek(struct file *fi
 
 	file->f_pos = real.file->f_pos;
 	ovl_inode_unlock(inode);
+	inode_unlock(inode);
 
 	fdput(real);