On 02/28/2014 03:48 AM, Xiubo Li wrote:
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...
There are actually no users of snd_soc_cache_{read,write}() left. Since all drivers using snd_soc_set_cache_io() are now using native regmap the path in hw_{read,write} that does call snd_soc_cache_{read,write}() is never hit.
If you want to avoid this theoretical issue just remove the functions.
So this patch fix this via doing the zero pionter check of it.
Signed-off-by: Xiubo Li Li.Xiubo@freescale.com
sound/soc/soc-cache.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index 375dc6d..bfed3e4 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -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;