net: w5100: check return value after calling platform_get_resource()

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>

diff --git a/drivers/net/ethernet/wiznet/w5100.c b/drivers/net/ethernet/wiznet/w5100.c
index 811815f..f974e70 100644 (file)
--- a/drivers/net/ethernet/wiznet/w5100.c
+++ b/drivers/net/ethernet/wiznet/w5100.c
@@ -1047,6 +1047,8 @@ 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