mmc: dw_mmc-pltfm: fix the potential NULL pointer dereference

platform_get_resource can be returned the NULL pointer.
Then regs->start should be referred to NULL Pointer.
devm_ioremap_resource() checks whether res is NULL or not.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
index c0bb0c7..dbbc430 100644 (file)
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -46,12 +46,13 @@ int dw_mci_pltfm_register(struct platform_device *pdev,
        host->pdata = pdev->dev.platform_data;
 
        regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       /* Get registers' physical base address */
-       host->phy_regs = regs->start;
        host->regs = devm_ioremap_resource(&pdev->dev, regs);
        if (IS_ERR(host->regs))
                return PTR_ERR(host->regs);
 
+       /* Get registers' physical base address */
+       host->phy_regs = regs->start;
+
        platform_set_drvdata(pdev, host);
        return dw_mci_probe(host);
 }