irqchip/mbigen: Fix potential NULL dereferencing

BugLink: https://bugs.launchpad.net/bugs/1692783
platform_get_resource() may return NULL, add proper
check to avoid potential NULL dereferencing.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linuxarm@huawei.com
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: MaJun <majun258@huawei.com>
Link: http://lkml.kernel.org/r/1494561328-39514-3-git-send-email-guohanjun@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
(cherry picked from commit ad7cc3c0c57d77b442db323056354d0e49833569)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index 0f5e66e96bd9a958a9d7f8ba3a021187ff01072f..2fa1e457190dbc37399f4a65d49234a32c52dd20 100644 (file)
--- 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) {