| From e4ae12de86984b0d2e8c5eaf1bc287122ce99d4f Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 26 Jul 2019 10:14:42 +0800 |
| Subject: ALSA: i2c: ak4xxx-adda: Fix a possible null pointer dereference in |
| build_adc_controls() |
| |
| From: Jia-Ju Bai <baijiaju1990@gmail.com> |
| |
| [ Upstream commit 2127c01b7f63b06a21559f56a8c81a3c6535bd1a ] |
| |
| 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 <baijiaju1990@gmail.com> |
| Signed-off-by: Takashi Iwai <tiwai@suse.de> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| sound/i2c/other/ak4xxx-adda.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c |
| index bf377dc192aa7..d33e02c317129 100644 |
| --- a/sound/i2c/other/ak4xxx-adda.c |
| +++ b/sound/i2c/other/ak4xxx-adda.c |
| @@ -789,11 +789,12 @@ 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; |
| -- |
| 2.20.1 |
| |
