[PATCH 3.2 130/221] ALSA: control: Add sanity checks for user ctl id name string

Ben Hutchings
2015-05-05T01:29:19Z

From: Takashi Iwai <tiwai@suse.de>

commit be3bb8236db2d0fcd705062ae2e2a9d75131222f upstream.

There was no check about the id string of user control elements, so we
accepted even a control element with an empty string, which is
obviously bogus. This patch adds more sanity checks of id strings.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
sound/core/control.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1164,6 +1164,10 @@ static int snd_ctl_elem_add(struct snd_c

if (info->count < 1)
return -EINVAL;
+ if (!*info->id.name)
+ return -EINVAL;
+ if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
+ return -EINVAL;
access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
SNDRV_CTL_ELEM_ACCESS_INACTIVE|