[tip:irq/urgent] irqchip/mbigen: Fix potential NULL dereferencing

[tip-bot for Hanjun Guo]

Commit-ID:  ad7cc3c0c57d77b442db323056354d0e49833569
Gitweb:     http://git.kernel.org/tip/ad7cc3c0c57d77b442db323056354d0e49833569
Author:     Hanjun Guo <hanjun.guo@xxxxxxxxxx>
AuthorDate: Fri, 12 May 2017 11:55:27 +0800
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 12 May 2017 10:25:37 +0200

irqchip/mbigen: Fix potential NULL dereferencing

platform_get_resource() may return NULL, add proper
check to avoid potential NULL dereferencing.

Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: linuxarm@xxxxxxxxxx
Cc: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Cc: MaJun <majun258@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1494561328-39514-3-git-send-email-guohanjun@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 drivers/irqchip/irq-mbigen.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index 0f5e66e..2fa1e45 100644
--- a/drivers/irqchip/irq-mbigen.c
+++ b/drivers/irqchip/irq-mbigen.c
@@ -337,6 +337,9 @@ static int mbigen_device_probe(struct platform_device *pdev)
 	mgn_chip->pdev = pdev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
 	mgn_chip->base = devm_ioremap(&pdev->dev, res->start,
 				      resource_size(res));
 	if (!mgn_chip->base) {