mtd: fix memory leak in mtd_dataflash

Fix a potential memory leak in mtd_dataflash driver.

The private data that is allocated when registering a DataFlash
device with the MTD subsystem is not released if an error occurs
when add_mtd_partitions() or add_mtd_device() is called.  Fix this
by adding an error path.  The memory is already released during a
remove.

Also, add a dev_set_drvdata(&spi->dev, NULL) before the kfree() so
that the spi device does not reference invalid data.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 93e3627be74c..19817404ce7d 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -636,6 +636,7 @@ add_dataflash_otp(struct spi_device *spi, char *name,
         struct mtd_info                 *device;
         struct flash_platform_data      *pdata = spi->dev.platform_data;
         char                            *otp_tag = "";
+        int                             err = 0;
 
         priv = kzalloc(sizeof *priv, GFP_KERNEL);
         if (!priv)
@@ -693,13 +694,23 @@ add_dataflash_otp(struct spi_device *spi, char *name,
 
                 if (nr_parts > 0) {
                         priv->partitioned = 1;
-                        return add_mtd_partitions(device, parts, nr_parts);
+                        err = add_mtd_partitions(device, parts, nr_parts);
+                        goto out;
                 }
         } else if (pdata && pdata->nr_parts)
                 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
                                 pdata->nr_parts, device->name);
 
-        return add_mtd_device(device) == 1 ? -ENODEV : 0;
+        if (add_mtd_device(device) == 1)
+                err = -ENODEV;
+
+out:
+        if (!err)
+                return 0;
+
+        dev_set_drvdata(&spi->dev, NULL);
+        kfree(priv);
+        return err;
 }
 
 static inline int __devinit
@@ -932,8 +943,10 @@ static int __devexit dataflash_remove(struct spi_device *spi)
                 status = del_mtd_partitions(&flash->mtd);
         else
                 status = del_mtd_device(&flash->mtd);
-        if (status == 0)
+        if (status == 0) {
+                dev_set_drvdata(&spi->dev, NULL);
                 kfree(flash);
+        }
         return status;
 }