diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 03b347afd46cfe1041ed45a30daafc196c6b08a9..8d60e5481af02290a4e0c0695806f77eb432862c 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -478,9 +478,7 @@ exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
 
 	nr_ports = board->num_ports ? board->num_ports : pcidev->device & 0x0f;
 
-	priv = devm_kzalloc(&pcidev->dev, sizeof(*priv) +
-			    sizeof(unsigned int) * nr_ports,
-			    GFP_KERNEL);
+	priv = devm_kzalloc(&pcidev->dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;