[PATCH AUTOSEL 5.4 094/175] drivers: net: davinci_mdio: fix potential NULL dereference in davinci_mdio_probe()

Sasha Levin
2020-06-09T00:07:35Z

From: Wei Yongjun <weiyongjun1@huawei.com>

[ Upstream commit e00edb4efbbc07425441a3be2aa87abaf5800d96 ]

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
since devm_ioremap() does not check input parameters for null.

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = \(platform_get_resource\|platform_get_resource_byname\)(pdev, t, n);
+ if (!res)
+ return -EINVAL;
... when != res == NULL
e = devm_ioremap(e1, res->start, e2);

Fixes: 03f66f067560 ("net: ethernet: ti: davinci_mdio: use devm_ioremap()")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/ti/davinci_mdio.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 38b7f6d35759..702fdc393da0 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -397,6 +397,8 @@ static int davinci_mdio_probe(struct platform_device *pdev)
data->dev = dev;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -EINVAL;
data->regs = devm_ioremap(dev, res->start, resource_size(res));
if (!data->regs)
return -ENOMEM;
--
2.25.1