diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
index 201b9875f9bbef778d2687b7750424ba55320de8..5cca73b8880b0dc1a95de176b31b0278bc0d2fb2 100644
--- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
@@ -313,6 +313,7 @@ int octeon_mbox_process_message(struct octeon_mbox *mbox)
 		return 0;
 	}
 
+	spin_unlock_irqrestore(&mbox->lock, flags);
 	WARN_ON(1);
 
 	return 0;