[PATCH 5.17 009/298] serial: 8250_aspeed_vuart: Fix potential NULL dereference in aspeed_vuart_probe

[Greg Kroah-Hartman]

From: Miaoqian Lin <linmq006@xxxxxxxxx>

[ Upstream commit 0e0fd55719fa081de6f9e5d9e6cef48efb04d34a ]

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference.

Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping")
Signed-off-by: Miaoqian Lin <linmq006@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220404143842.16960-1-linmq006@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/serial/8250/8250_aspeed_vuart.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index c2cecc6f47db..179bb1375636 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -429,6 +429,8 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 	timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 
 	memset(&port, 0, sizeof(port));
 	port.port.private_data = vuart;
-- 
2.35.1