[PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[Mark Brown]

When reporting the pointer for a compressed stream we report the current
I/O frame position by dividing the position by the number of channels
multiplied by the number of container bytes. These values default to 0 and
are only configured as part of setting the stream parameters so this allows
a divide by zero to be configured. Validate that they are non zero,
returning an error if not

Fixes: c1a731c71359 ("ASoC: SOF: compress: Add support for computing timestamps")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
---
 sound/soc/sof/compress.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/sof/compress.c b/sound/soc/sof/compress.c
index 96570121aae0..90f056eae1c3 100644
--- a/sound/soc/sof/compress.c
+++ b/sound/soc/sof/compress.c
@@ -379,6 +379,9 @@ static int sof_compr_pointer(struct snd_soc_component *component,
 	if (!spcm)
 		return -EINVAL;
 
+	if (!sstream->channels || !sstream->sample_container_bytes)
+		return -EBUSY;
+
 	tstamp->sampling_rate = sstream->sampling_rate;
 	tstamp->copied_total = sstream->copied_total;
 	tstamp->pcm_io_frames = div_u64(spcm->stream[cstream->direction].posn.dai_posn,

---
base-commit: c369299895a591d96745d6492d4888259b004a9e
change-id: 20260326-asoc-compress-tstamp-params-296f38f15217

Best regards,
--  
Mark Brown <broonie@kernel.org>

RE: [PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[Liao, Bard]

> -----Original Message-----
> From: Mark Brown <broonie@kernel.org>
> Sent: Thursday, March 26, 2026 10:53 PM
> To: Liam Girdwood <lgirdwood@gmail.com>; Peter Ujfalusi
> <peter.ujfalusi@linux.intel.com>; Bard Liao <yung-
> chuan.liao@linux.intel.com>; Ranjani Sridharan
> <ranjani.sridharan@linux.intel.com>; Daniel Baluta <daniel.baluta@nxp.com>;
> Kai Vehmanen <kai.vehmanen@linux.intel.com>; Pierre-Louis Bossart <pierre-
> louis.bossart@linux.dev>; Jaroslav Kysela <perex@perex.cz>; Takashi Iwai
> <tiwai@suse.com>; Paul Olaru <paul.olaru@oss.nxp.com>; Laurentiu Mihalcea
> <laurentiu.mihalcea@nxp.com>
> Cc: sound-open-firmware@alsa-project.org; linux-sound@vger.kernel.org;
> linux-kernel@vger.kernel.org; Mark Brown <broonie@kernel.org>;
> stable@vger.kernel.org
> Subject: [PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured
> streams
> 
> When reporting the pointer for a compressed stream we report the current
> I/O frame position by dividing the position by the number of channels
> multiplied by the number of container bytes. These values default to 0 and
> are only configured as part of setting the stream parameters so this allows
> a divide by zero to be configured. Validate that they are non zero,
> returning an error if not
> 
> Fixes: c1a731c71359 ("ASoC: SOF: compress: Add support for computing
> timestamps")
> Signed-off-by: Mark Brown <broonie@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  sound/soc/sof/compress.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/sound/soc/sof/compress.c b/sound/soc/sof/compress.c
> index 96570121aae0..90f056eae1c3 100644
> --- a/sound/soc/sof/compress.c
> +++ b/sound/soc/sof/compress.c
> @@ -379,6 +379,9 @@ static int sof_compr_pointer(struct
> snd_soc_component *component,
>  	if (!spcm)
>  		return -EINVAL;
> 
> +	if (!sstream->channels || !sstream->sample_container_bytes)
> +		return -EBUSY;

Sorry, but why it is BUSY in this case?

> +
>  	tstamp->sampling_rate = sstream->sampling_rate;
>  	tstamp->copied_total = sstream->copied_total;
>  	tstamp->pcm_io_frames = div_u64(spcm->stream[cstream-
> >direction].posn.dai_posn,
> 
> ---
> base-commit: c369299895a591d96745d6492d4888259b004a9e
> change-id: 20260326-asoc-compress-tstamp-params-296f38f15217
> 
> Best regards,
> --
> Mark Brown <broonie@kernel.org>

Re: [PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[Péter Ujfalusi]

On 26/03/2026 16:52, Mark Brown wrote:
> When reporting the pointer for a compressed stream we report the current
> I/O frame position by dividing the position by the number of channels
> multiplied by the number of container bytes. These values default to 0 and
> are only configured as part of setting the stream parameters so this allows
> a divide by zero to be configured. Validate that they are non zero,
> returning an error if not
> 
> Fixes: c1a731c71359 ("ASoC: SOF: compress: Add support for computing timestamps")
> Signed-off-by: Mark Brown <broonie@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  sound/soc/sof/compress.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/sound/soc/sof/compress.c b/sound/soc/sof/compress.c
> index 96570121aae0..90f056eae1c3 100644
> --- a/sound/soc/sof/compress.c
> +++ b/sound/soc/sof/compress.c
> @@ -379,6 +379,9 @@ static int sof_compr_pointer(struct snd_soc_component *component,
>  	if (!spcm)
>  		return -EINVAL;
>  
> +	if (!sstream->channels || !sstream->sample_container_bytes)
> +		return -EBUSY;
> +

Is this a theoretical fix?
I don't think this can happen in real world as set_params would need to
fail and if that failed then applications would not ask for a pointer as
the compress stream cannot be even started.

>  	tstamp->sampling_rate = sstream->sampling_rate;
>  	tstamp->copied_total = sstream->copied_total;
>  	tstamp->pcm_io_frames = div_u64(spcm->stream[cstream->direction].posn.dai_posn,
> 
> ---
> base-commit: c369299895a591d96745d6492d4888259b004a9e
> change-id: 20260326-asoc-compress-tstamp-params-296f38f15217
> 
> Best regards,
> --  
> Mark Brown <broonie@kernel.org>
> 
> 

-- 
Péter

Re: [PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[Mark Brown]

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On Fri, Mar 27, 2026 at 02:09:40AM +0000, Liao, Bard wrote:

> > +	if (!sstream->channels || !sstream->sample_container_bytes)
> > +		return -EBUSY;

> Sorry, but why it is BUSY in this case?

-EBUSY is often "wrong state".  Could also be -EINVAL, it doesn't super
make a difference I think - nobody should actually be doing this.

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Re: [PATCH] ASoC: SOF: Don't allow pointer operations on unconfigured streams

[Mark Brown]

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On Fri, Mar 27, 2026 at 11:49:41AM +0200, Péter Ujfalusi wrote:
> On 26/03/2026 16:52, Mark Brown wrote:

> > +	if (!sstream->channels || !sstream->sample_container_bytes)
> > +		return -EBUSY;
> > +

> Is this a theoretical fix?
> I don't think this can happen in real world as set_params would need to
> fail and if that failed then applications would not ask for a pointer as
> the compress stream cannot be even started.

Yes, it's not something that would happen in the real world with a non
buggy (or hostile) userspace.  Still, we shouldn't leave this stuff
open.

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