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>

1 files changed, 3 insertions, 2 deletions

diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index adbc68ce9050..15d2779074ef 100644
--- 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;