reset: hisilicon: fix potential NULL pointer dereference

BugLink: https://bugs.launchpad.net/bugs/1836802
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/clk/hisilicon/reset.c b/drivers/clk/hisilicon/reset.c
index 2a5015c736ce6d604d371c0bcd2a894d1ae4015f..43e82fa644226894bb520f4134740f98577ac297 100644 (file)
--- a/drivers/clk/hisilicon/reset.c
+++ b/drivers/clk/hisilicon/reset.c
@@ -109,9 +109,8 @@ struct hisi_reset_controller *hisi_reset_init(struct platform_device *pdev)
                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);