[PATCH 3.4 091/172] ALSA: control: Add sanity checks for user ctl id name string

lizf
2015-06-16T08:46:48Z

From: Takashi Iwai <tiwai@suse.de>

3.4.108-rc1 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@suse.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
sound/core/control.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/sound/core/control.c b/sound/core/control.c
index e773d5e..8fb4d24 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1164,6 +1164,10 @@ 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|
--
1.9.1