devm_kasprintf() returns NULL when memory allocation fails. Currently,
avs_component_probe() does not check for this case, which results in a
NULL pointer dereference.

Fixes: 739c031110da ("ASoC: Intel: avs: Provide support for fallback topology")
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Ethan Carter Edwards <ethan@ethancedwards.com>
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
---
V1 -> V2: No functional changes, just correct title and redundant commit
message.

 sound/soc/intel/avs/pcm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/intel/avs/pcm.c b/sound/soc/intel/avs/pcm.c
index dac463390da1..7072bcf4e56f 100644
--- a/sound/soc/intel/avs/pcm.c
+++ b/sound/soc/intel/avs/pcm.c
@@ -927,7 +927,8 @@ static int avs_component_probe(struct snd_soc_component *component)
 		else
 			mach->tplg_filename = devm_kasprintf(adev->dev, GFP_KERNEL,
 							     "hda-generic-tplg.bin");
-
+		if (!mach->tplg_filename)
+			return -ENOMEM;
 		filename = kasprintf(GFP_KERNEL, "%s/%s", component->driver->topology_name_prefix,
 				     mach->tplg_filename);
 		if (!filename)
-- 
2.34.1

On Wed, 02 Apr 2025 22:14:11 +0800, Henry Martin wrote:
> devm_kasprintf() returns NULL when memory allocation fails. Currently,
> avs_component_probe() does not check for this case, which results in a
> NULL pointer dereference.
> 
> 

Applied to

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

Thanks!

[1/1] ASoC: Intel: avs: Fix null-ptr-deref in avs_component_probe()
      commit: 95f723cf141b95e3b3a5b92cf2ea98a863fe7275

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

> devm_kasprintf() returns NULL when memory allocation fails. Currently,
…
                                                       failed?

Can a summary phrase like “Prevent null pointer dereference
in avs_component_probe()” a bit nicer?


…
> +++ b/sound/soc/intel/avs/pcm.c
> @@ -927,7 +927,8 @@ static int avs_component_probe(struct snd_soc_component *component)
>  		else
>  			mach->tplg_filename = devm_kasprintf(adev->dev, GFP_KERNEL,
>  							     "hda-generic-tplg.bin");
> -
> +		if (!mach->tplg_filename)
> +			return -ENOMEM;

Can a blank line be desirable after such a statement?


Would another source code transformation become helpful with an additional update step?

-		if (((vendor_id >> 16) & 0xFFFF) == 0x8086)
-			mach->tplg_filename = devm_kasprintf(adev->dev, GFP_KERNEL,
-							     "hda-8086-generic-tplg.bin");
-		else
-			mach->tplg_filename = devm_kasprintf(adev->dev, GFP_KERNEL,
-							     "hda-generic-tplg.bin");
+		mach->tplg_filename = devm_kasprintf(adev->dev, GFP_KERNEL,
+						     (((vendor_id >> 16) & 0xFFFF) == 0x8086)
+						     ? "hda-8086-generic-tplg.bin"
+						     : "hda-generic-tplg.bin");


Regards,
Markus

On Wed, Apr 02, 2025 at 09:18:27PM +0200, Markus Elfring wrote:
> > devm_kasprintf() returns NULL when memory allocation fails. Currently,
> …
>                                                        failed?
> 
> Can a summary phrase like “Prevent null pointer dereference
> in avs_component_probe()” a bit nicer?

Feel free to ignore Markus, he has a long history of sending
unhelpful review comments and continues to ignore repeated requests
to stop.