pinctrl: renesas: core: Fix possible null-ptr-deref in sh_pfc_map_res…

…ources()

[ Upstream commit 5376e3d ]

It will cause null-ptr-deref when using 'res', if platform_get_resource()
returns NULL, so move using 'res' after devm_ioremap_resource() that
will check it to avoid null-ptr-deref.
And use devm_platform_get_and_ioremap_resource() to simplify code.

Fixes: c7977ec ("pinctrl: sh-pfc: Convert to platform_get_*()")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220429082637.1308182-1-yangyingliang@huawei.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/pinctrl/renesas/core.c

@@ -71,12 +71,11 @@ static int sh_pfc_map_resources(struct sh_pfc *pfc,
 
 	/* Fill them. */
 	for (i = 0; i < num_windows; i++) {
-		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
-		windows->phys = res->start;
-		windows->size = resource_size(res);
-		windows->virt = devm_ioremap_resource(pfc->dev, res);
+		windows->virt = devm_platform_get_and_ioremap_resource(pdev, i, &res);
 		if (IS_ERR(windows->virt))
 			return -ENOMEM;
+		windows->phys = res->start;
+		windows->size = resource_size(res);
 		windows++;
 	}
 	for (i = 0; i < num_irqs; i++)