[patch] ALSA: compress: info leak in snd_compr_get_caps()

[Dan Carpenter <dan.carpenter@oracle.com>]

If the ->get_caps() function doesn't clear the buffer then there would
stack information leaked to userspace.  For example,
soc_compr_get_caps() can return success without clearing the buffer.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Perhaps the soc_compr_get_caps() function should return an error code
if the platform->driver->compr_ops is NULL.  I'm not sure about that,
and it's a separate issue anyway.

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index c84abc8..8d3190a 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -375,6 +375,7 @@ snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
 	if (!stream->ops->get_caps)
 		return -ENXIO;
 
+	memset(&caps, 0, sizeof(caps));
 	retval = stream->ops->get_caps(stream, &caps);
 	if (retval)
 		goto out;