From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sun, 21 Apr 2013 11:07:29 +0000
Subject: [patch] ALSA: compress: info leak in snd_compr_get_caps()
Message-Id: <20130421110729.GA6171@elgon.mountain>
List-Id: <kernel-janitors.vger.kernel.org>
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To: Jaroslav Kysela <perex@perex.cz>
Cc: alsa-devel@alsa-project.org, Takashi Iwai <tiwai@suse.de>, kernel-janitors@vger.kernel.org, Vinod Koul <vinod.koul@intel.com>, Jeeja KP <jeeja.kp@intel.com>, Namarta Kohli <namartax.kohli@intel.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;