ASoC: Fix soc-cache buffer overflow bug

Make sure we stay within the cache boundaries when updating the
register cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index adbc68c..15d2779 100644 (file)
--- a/sound/soc/soc-cache.c
+++ b/sound/soc/soc-cache.c
@@ -203,8 +203,9 @@ static int snd_soc_8_16_write(struct snd_soc_codec *codec, unsigned int reg,
        data[1] = (value >> 8) & 0xff;
        data[2] = value & 0xff;
 
-       if (!snd_soc_codec_volatile_register(codec, reg))
-               reg_cache[reg] = value;
+       if (!snd_soc_codec_volatile_register(codec, reg)
+               && reg < codec->driver->reg_cache_size)
+                       reg_cache[reg] = value;
 
        if (codec->cache_only) {
                codec->cache_sync = 1;