Re: [PATCH] ASoC: Intel: Skylake: skl-topology: Fix OOPs ib skl_tplg_complete

From: "Gorski, Mateusz" <mateusz.gorski@linux.intel.com>
To: Ricardo Ribalda <ribalda@chromium.org>,
	Cezary Rojewski <cezary.rojewski@intel.com>,
	Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Liam Girdwood <liam.r.girdwood@linux.intel.com>,
	Jie Yang <yang.jie@linux.intel.com>,
	Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
	Takashi Iwai <tiwai@suse.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ASoC: Intel: Skylake: skl-topology: Fix OOPs ib skl_tplg_complete
Date: Mon, 14 Dec 2020 18:07:23 +0100	[thread overview]
Message-ID: <6b933ad0-2b54-33de-4d74-c176efd4d110@linux.intel.com> (raw)
In-Reply-To: <20201211170629.871085-1-ribalda@chromium.org>

> If dobj->control is not initialized we end up in an OOPs during
> skl_tplg_complete:
>
> [   26.553358] BUG: kernel NULL pointer dereference, address:
> 0000000000000078
> [   26.561151] #PF: supervisor read access in kernel mode
> [   26.566897] #PF: error_code(0x0000) - not-present page
> [   26.572642] PGD 0 P4D 0
> [   26.575479] Oops: 0000 [#1] PREEMPT SMP PTI
> [   26.580158] CPU: 2 PID: 2082 Comm: udevd Tainted: G         C
> 5.4.81 #4
> [   26.588232] Hardware name: HP Soraka/Soraka, BIOS
> Google_Soraka.10431.106.0 12/03/2019
> [   26.597082] RIP: 0010:skl_tplg_complete+0x70/0x144 [snd_soc_skl]
>
> Fixes: 2d744ecf2b98 ("ASoC: Intel: Skylake: Automatic DMIC format configuration according to information from NHL")
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>   sound/soc/intel/skylake/skl-topology.c | 15 ++++++++-------
>   1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/sound/soc/intel/skylake/skl-topology.c b/sound/soc/intel/skylake/skl-topology.c
> index 40bee10b0c65..0955cbb4e918 100644
> --- a/sound/soc/intel/skylake/skl-topology.c
> +++ b/sound/soc/intel/skylake/skl-topology.c
> @@ -3619,19 +3619,20 @@ static void skl_tplg_complete(struct snd_soc_component *component)
>   
>   	list_for_each_entry(dobj, &component->dobj_list, list) {
>   		struct snd_kcontrol *kcontrol = dobj->control.kcontrol;
> -		struct soc_enum *se =
> -			(struct soc_enum *)kcontrol->private_value;
> -		char **texts = dobj->control.dtexts;
> +		struct soc_enum *se;
> +		char **texts;
>   		char chan_text[4];
>   
> -		if (dobj->type != SND_SOC_DOBJ_ENUM ||
> -		    dobj->control.kcontrol->put !=
> -		    skl_tplg_multi_config_set_dmic)
> +		if (dobj->type != SND_SOC_DOBJ_ENUM || !kcontrol ||
> +		    kcontrol->put != skl_tplg_multi_config_set_dmic)
>   			continue;
> +
> +		se = (struct soc_enum *)kcontrol->private_value;
> +		texts = dobj->control.dtexts;
>   		sprintf(chan_text, "c%d", mach->mach_params.dmic_num);
>   
>   		for (i = 0; i < se->items; i++) {
> -			struct snd_ctl_elem_value val;
> +			struct snd_ctl_elem_value val = {};
>   
>   			if (strstr(texts[i], chan_text)) {
>   				val.value.enumerated.item[0] = i;

Hi Ricardo,

there is another thread regarding this issue (with fix provided by 
Lukasz Majczak), you can find it here:

     https://www.spinics.net/lists/stable/msg431524.html

Thanks,
Mateusz