ALSA: ASoC: Fix double free and memory leak in many codec drivers

Many SoC audio codec drivers have improper freeing of memory in error
paths.

* codec is allocated in the platform device probe function, but is not
  freed there in case of error. Instead it is freed in the i2c device
  probe function's error path. However the success or failure of both
  functions is not linked, so this could result in a double free (if
  the platform device is successfully probed, the i2c device probing
  fails and then the platform driver is unregistered.)

* codec->private_data is allocated in many platform device probe
  functions but not freed in their error paths.

This patch hopefully solves all these problems.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index 369d39c3f745..9402fcaf04fa 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -596,10 +596,9 @@ static int wm8731_codec_probe(struct i2c_adapter *adap, int addr, int kind)
         client_template.addr = addr;
 
         i2c = kmemdup(&client_template, sizeof(client_template), GFP_KERNEL);
-        if (i2c == NULL) {
-                kfree(codec);
+        if (i2c == NULL)
                 return -ENOMEM;
-        }
+
         i2c_set_clientdata(i2c, codec);
         codec->control_data = i2c;
 
@@ -617,7 +616,6 @@ static int wm8731_codec_probe(struct i2c_adapter *adap, int addr, int kind)
         return ret;
 
 err:
-        kfree(codec);
         kfree(i2c);
         return ret;
 }
@@ -693,6 +691,11 @@ static int wm8731_probe(struct platform_device *pdev)
 #else
         /* Add other interfaces here */
 #endif
+
+        if (ret != 0) {
+                kfree(codec->private_data);
+                kfree(codec);
+        }
         return ret;
 }