In build_adc_controls(), there is an if statement on line 773 to check
whether ak->adc_info is NULL:
if (! ak->adc_info ||
! ak->adc_info[mixer_ch].switch_name)
When ak->adc_info is NULL, it is used on line 792:
knew.name = ak->adc_info[mixer_ch].selector_name;
Thus, a possible null-pointer dereference may occur.
To fix this bug, referring to lines 773 and 774, ak->adc_info
and ak->adc_info[mixer_ch].selector_name are checked before being used.
This bug is found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <[email protected]>
---
sound/i2c/other/ak4xxx-adda.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c
index 5f59316f982a..9a891470e84a 100644
--- a/sound/i2c/other/ak4xxx-adda.c
+++ b/sound/i2c/other/ak4xxx-adda.c
@@ -775,11 +775,13 @@ static int build_adc_controls(struct snd_akm4xxx *ak)
return err;
memset(&knew, 0, sizeof(knew));
- knew.name = ak->adc_info[mixer_ch].selector_name;
- if (!knew.name) {
+ if (! ak->adc_info ||
+ ! ak->adc_info[mixer_ch].selector_name) {
knew.name = "Capture Channel";
knew.index = mixer_ch + ak->idx_offset * 2;
}
+ else
+ knew.name = ak->adc_info[mixer_ch].selector_name;
knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
knew.info = ak4xxx_capture_source_info;
--
2.17.0
On Thu, 25 Jul 2019 10:27:33 +0200,
Jia-Ju Bai wrote:
>
> In build_adc_controls(), there is an if statement on line 773 to check
> whether ak->adc_info is NULL:
> if (! ak->adc_info ||
> ! ak->adc_info[mixer_ch].switch_name)
>
> When ak->adc_info is NULL, it is used on line 792:
> knew.name = ak->adc_info[mixer_ch].selector_name;
>
> Thus, a possible null-pointer dereference may occur.
>
> To fix this bug, referring to lines 773 and 774, ak->adc_info
> and ak->adc_info[mixer_ch].selector_name are checked before being used.
>
> This bug is found by a static analysis tool STCheck written by us.
>
> Signed-off-by: Jia-Ju Bai <[email protected]>
> ---
> sound/i2c/other/ak4xxx-adda.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c
> index 5f59316f982a..9a891470e84a 100644
> --- a/sound/i2c/other/ak4xxx-adda.c
> +++ b/sound/i2c/other/ak4xxx-adda.c
> @@ -775,11 +775,13 @@ static int build_adc_controls(struct snd_akm4xxx *ak)
> return err;
>
> memset(&knew, 0, sizeof(knew));
> - knew.name = ak->adc_info[mixer_ch].selector_name;
> - if (!knew.name) {
> + if (! ak->adc_info ||
> + ! ak->adc_info[mixer_ch].selector_name) {
> knew.name = "Capture Channel";
> knew.index = mixer_ch + ak->idx_offset * 2;
> }
> + else
> + knew.name = ak->adc_info[mixer_ch].selector_name;
>
> knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
> knew.info = ak4xxx_capture_source_info;
The code change itself looks good, but please follow the standard
coding style. In short: please run checkpatch.pl, fix errors (some
warnings may be ignored) and resubmit.
thanks,
Takashi
On 2019/7/25 23:52, Takashi Iwai wrote:
> On Thu, 25 Jul 2019 10:27:33 +0200,
> Jia-Ju Bai wrote:
>> In build_adc_controls(), there is an if statement on line 773 to check
>> whether ak->adc_info is NULL:
>> if (! ak->adc_info ||
>> ! ak->adc_info[mixer_ch].switch_name)
>>
>> When ak->adc_info is NULL, it is used on line 792:
>> knew.name = ak->adc_info[mixer_ch].selector_name;
>>
>> Thus, a possible null-pointer dereference may occur.
>>
>> To fix this bug, referring to lines 773 and 774, ak->adc_info
>> and ak->adc_info[mixer_ch].selector_name are checked before being used.
>>
>> This bug is found by a static analysis tool STCheck written by us.
>>
>> Signed-off-by: Jia-Ju Bai <[email protected]>
>> ---
>> sound/i2c/other/ak4xxx-adda.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c
>> index 5f59316f982a..9a891470e84a 100644
>> --- a/sound/i2c/other/ak4xxx-adda.c
>> +++ b/sound/i2c/other/ak4xxx-adda.c
>> @@ -775,11 +775,13 @@ static int build_adc_controls(struct snd_akm4xxx *ak)
>> return err;
>>
>> memset(&knew, 0, sizeof(knew));
>> - knew.name = ak->adc_info[mixer_ch].selector_name;
>> - if (!knew.name) {
>> + if (! ak->adc_info ||
>> + ! ak->adc_info[mixer_ch].selector_name) {
>> knew.name = "Capture Channel";
>> knew.index = mixer_ch + ak->idx_offset * 2;
>> }
>> + else
>> + knew.name = ak->adc_info[mixer_ch].selector_name;
>>
>> knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
>> knew.info = ak4xxx_capture_source_info;
> The code change itself looks good, but please follow the standard
> coding style. In short: please run checkpatch.pl, fix errors (some
> warnings may be ignored) and resubmit.
Okay, thanks for the advice.
I will send a v2 patch.
Best wishes,
Jia-Ju Bai