ASoC: cache: Do the codec->reg_cache zero pionter check

For the snd_soc_cache_init(), the reg_size maybe zero and then the value
of codec->reg_cache, which is alloced via kzalloc, maybe equal to
ZERO_SIZE_PTR. If the reg parameter of snd_soc_cache_write() is large enough,
the cache[idx] = val maybe cause the kernel crash...

So this patch fix this via doing the zero pionter check of it.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Xiubo Li 2014-02-28 10:48:19 +08:00 committed by Mark Brown
parent 939d9f1699
commit 931f27c6e8

View File

@ -96,8 +96,7 @@ int snd_soc_cache_exit(struct snd_soc_codec *codec)
{
dev_dbg(codec->dev, "ASoC: Destroying cache for %s codec\n",
codec->name);
if (!codec->reg_cache)
return 0;
kfree(codec->reg_cache);
codec->reg_cache = NULL;
return 0;
@ -117,8 +116,9 @@ int snd_soc_cache_read(struct snd_soc_codec *codec,
return -EINVAL;
mutex_lock(&codec->cache_rw_mutex);
*value = snd_soc_get_cache_val(codec->reg_cache, reg,
codec->driver->reg_word_size);
if (!ZERO_OR_NULL_PTR(codec->reg_cache))
*value = snd_soc_get_cache_val(codec->reg_cache, reg,
codec->driver->reg_word_size);
mutex_unlock(&codec->cache_rw_mutex);
return 0;
@ -136,8 +136,9 @@ int snd_soc_cache_write(struct snd_soc_codec *codec,
unsigned int reg, unsigned int value)
{
mutex_lock(&codec->cache_rw_mutex);
snd_soc_set_cache_val(codec->reg_cache, reg, value,
codec->driver->reg_word_size);
if (!ZERO_OR_NULL_PTR(codec->reg_cache))
snd_soc_set_cache_val(codec->reg_cache, reg, value,
codec->driver->reg_word_size);
mutex_unlock(&codec->cache_rw_mutex);
return 0;