[PATCH 3.12 047/155] ALSA: control: Add sanity checks for user ctl id name string

From: Jiri Slaby
Date: Tue Apr 07 2015 - 09:28:20 EST


From: Takashi Iwai <tiwai@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

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@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
sound/core/control.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/sound/core/control.c b/sound/core/control.c
index 98a29b26c5f4..f2082a35b890 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1168,6 +1168,10 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,

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|
--
2.3.4

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