mfd: asic3: Fix potential null pointer dereference

We previously assumed 'mem_sdio' could be null but it is
dereferenced in ioremap(). Add a check to avoid a potential
null pointer dereference error.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
index 9f6294f2a070..9fc4186d4132 100644
--- a/drivers/mfd/asic3.c
+++ b/drivers/mfd/asic3.c
@@ -899,13 +899,15 @@ static int __init asic3_mfd_probe(struct platform_device *pdev,
         ds1wm_resources[0].end   >>= asic->bus_shift;
 
         /* MMC */
-        asic->tmio_cnf = ioremap((ASIC3_SD_CONFIG_BASE >> asic->bus_shift) +
+        if (mem_sdio) {
+                asic->tmio_cnf = ioremap((ASIC3_SD_CONFIG_BASE >> asic->bus_shift) +
                                  mem_sdio->start,
                                  ASIC3_SD_CONFIG_SIZE >> asic->bus_shift);
-        if (!asic->tmio_cnf) {
-                ret = -ENOMEM;
-                dev_dbg(asic->dev, "Couldn't ioremap SD_CONFIG\n");
-                goto out;
+                if (!asic->tmio_cnf) {
+                        ret = -ENOMEM;
+                        dev_dbg(asic->dev, "Couldn't ioremap SD_CONFIG\n");
+                        goto out;
+                }
         }
         asic3_mmc_resources[0].start >>= asic->bus_shift;
         asic3_mmc_resources[0].end   >>= asic->bus_shift;