[PATCH 4.9 41/83] reset: hisilicon: fix potential NULL pointer dereference

Greg Kroah-Hartman
2018-11-19T16:53:59Z

From: Gustavo A. R. Silva <gustavo@embeddedor.com>

commit e9a2310fb689151166df7fd9971093362d34bd79 upstream.

There is a potential execution path in which function
platform_get_resource() returns NULL. If this happens,
we will end up having a NULL pointer dereference.

Fix this by replacing devm_ioremap with devm_ioremap_resource,
which has the NULL check and the memory region request.

This code was detected with the help of Coccinelle.

Cc: stable@vger.kernel.org
Fixes: 97b7129cd2af ("reset: hisilicon: change the definition of hisi_reset_init")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/clk/hisilicon/reset.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/clk/hisilicon/reset.c
+++ b/drivers/clk/hisilicon/reset.c
@@ -109,9 +109,8 @@ struct hisi_reset_controller *hisi_reset
return NULL;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- rstc->membase = devm_ioremap(&pdev->dev,
- res->start, resource_size(res));
- if (!rstc->membase)
+ rstc->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(rstc->membase))
return NULL;

spin_lock_init(&rstc->lock);