[PATCH] ASoC: wm_adsp: Pass full name to snd_ctl_notify

[PATCH] ASoC: wm_adsp: Pass full name to snd_ctl_notify

[Charles Keepax]

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

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>
---
 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 410cca57da52d..344bd2c33bea1 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -2049,6 +2049,7 @@ 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);
@@ -2059,8 +2060,25 @@ 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);
 
-- 
2.11.0

Re: [PATCH] ASoC: wm_adsp: Pass full name to snd_ctl_notify

[Mark Brown]

On Thu, 1 Oct 2020 16:24:25 +0100, Charles Keepax wrote:
> 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.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: wm_adsp: Pass full name to snd_ctl_notify
      commit: 20441614d89867142060d3bcd79cc111d8ba7a8e

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark