[PATCH 4.4 48/69] mmc: dw_mmc-pltfm: fix the potential NULL pointer dereference

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jaehoon Chung <jh80.chung@samsung.com>

commit 45c7a4908a307a023e237a64a3eadcafc4836493 upstream.

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>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mmc/host/dw_mmc-pltfm.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -59,12 +59,13 @@ int dw_mci_pltfm_register(struct platfor
 	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);
 }