From fb1ee027878b30f7545c77b1cdf1f61136d21092 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Tue, 31 Aug 2021 16:40:18 +0800
Subject: [PATCH] net: w5100: check return value after calling
 platform_get_resource()

[ Upstream commit a39ff4a47f3e1da3b036817ef436b1a9be10783a ]

It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/wiznet/w5100.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/wiznet/w5100.c b/drivers/net/ethernet/wiznet/w5100.c
index c0d181a7f83a..0b7135a3c585 100644
--- a/drivers/net/ethernet/wiznet/w5100.c
+++ b/drivers/net/ethernet/wiznet/w5100.c
@@ -1052,6 +1052,8 @@ static int w5100_mmio_probe(struct platform_device *pdev)
 		mac_addr = data->mac_addr;
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -EINVAL;
 	if (resource_size(mem) < W5100_BUS_DIRECT_SIZE)
 		ops = &w5100_mmio_indirect_ops;
 	else