[PATCH 5.8 293/633] ASoC: wm_adsp: Pass full name to snd_ctl_notify

Greg Kroah-Hartman
2020-10-27T15:04:10Z

From: Adam Brickman <Adam.Brickman@cirrus.com>

[ Upstream commit 20441614d89867142060d3bcd79cc111d8ba7a8e ]

A call to wm_adsp_write_ctl() could cause a kernel crash if it
does not retrieve a valid kcontrol from snd_soc_card_get_kcontrol().
This can happen due to a missing control name prefix. Then,
snd_ctl_notify() crashes when it tries to use the id field.

Modified wm_adsp_write_ctl() to incorporate the name_prefix (if applicable)
such that it is able to retrieve a valid id field from the kcontrol
once the platform has booted.

Fixes: eb65ccdb0836 ("ASoC: wm_adsp: Expose mixer control API")
Signed-off-by: Adam Brickman <Adam.Brickman@cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20201001152425.8590-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/codecs/wm_adsp.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 519ca2e696372..18f62fde92537 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -2043,6 +2043,7 @@ int wm_adsp_write_ctl(struct wm_adsp *dsp, const char *name, int type,
{
struct wm_coeff_ctl *ctl;
struct snd_kcontrol *kcontrol;
+ char ctl_name[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
int ret;

ctl = wm_adsp_get_ctl(dsp, name, type, alg);
@@ -2053,8 +2054,25 @@ int wm_adsp_write_ctl(struct wm_adsp *dsp, const char *name, int type,
return -EINVAL;

ret = wm_coeff_write_ctrl(ctl, buf, len);
+ if (ret)
+ return ret;
+
+ if (ctl->flags & WMFW_CTL_FLAG_SYS)
+ return 0;
+
+ if (dsp->component->name_prefix)
+ snprintf(ctl_name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN, "%s %s",
+ dsp->component->name_prefix, ctl->name);
+ else
+ snprintf(ctl_name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN, "%s",
+ ctl->name);
+
+ kcontrol = snd_soc_card_get_kcontrol(dsp->component->card, ctl_name);
+ if (!kcontrol) {
+ adsp_err(dsp, "Can't find kcontrol %s\n", ctl_name);
+ return -EINVAL;
+ }

- kcontrol = snd_soc_card_get_kcontrol(dsp->component->card, ctl->name);
snd_ctl_notify(dsp->component->card->snd_card,
SNDRV_CTL_EVENT_MASK_VALUE, &kcontrol->id);

--
2.25.1