[PATCH] ASoC: cs35l56-shared-test: Fix possible null pointer dereference

[PATCH] ASoC: cs35l56-shared-test: Fix possible null pointer dereference

[Ethan Tidmore]

The struct regmap_config is dereferenced before its check. Also, after
it is checked priv->reg_offset is assigned to regmap_config->reg_base,
making the removed line redundant.

Detected by Smatch:
sound/soc/codecs/cs35l56-shared-test.c:681 cs35l56_shared_test_case_base_init()
warn: variable dereferenced before check 'regmap_config' (see line 665)

Fixes: a6f7c21accb5f ("ASoC: cs35l56-shared-test: Subtract reg_base offset in dummy regmap")
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
---
 sound/soc/codecs/cs35l56-shared-test.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/sound/soc/codecs/cs35l56-shared-test.c b/sound/soc/codecs/cs35l56-shared-test.c
index 5b2b915559a9..4f52c8a192e5 100644
--- a/sound/soc/codecs/cs35l56-shared-test.c
+++ b/sound/soc/codecs/cs35l56-shared-test.c
@@ -662,7 +662,6 @@ static int cs35l56_shared_test_case_base_init(struct kunit *test, u8 type, u8 re
 
 	test->priv = priv;
 	priv->test = test;
-	priv->reg_offset = regmap_config->reg_base;
 
 	/* Create dummy amp driver dev */
 	priv->amp_dev = faux_device_create("cs35l56_shared_test_drv", NULL, NULL);
-- 
2.54.0

Re: [PATCH] ASoC: cs35l56-shared-test: Fix possible null pointer dereference

[Richard Fitzgerald]

On 23/05/2026 10:15 pm, Ethan Tidmore wrote:
> The struct regmap_config is dereferenced before its check. Also, after
> it is checked priv->reg_offset is assigned to regmap_config->reg_base,
> making the removed line redundant.
> 
> Detected by Smatch:
> sound/soc/codecs/cs35l56-shared-test.c:681 cs35l56_shared_test_case_base_init()
> warn: variable dereferenced before check 'regmap_config' (see line 665)
> 
> Fixes: a6f7c21accb5f ("ASoC: cs35l56-shared-test: Subtract reg_base offset in dummy regmap")

If you apply this change on top of commit a6f7c21accb5f it would break
the test because it removes the line instead of moving it to a different
place.

Something weird has happened here. I already fixed this in V4 of the
patch series. It turns out that V3 was already merged, but I didn't
receive a merge notificiation. V4 has then been merged on top so Mark's
for-7.2 and for-next contain the combination of V3 and V4 but this
fix commit doesn't make sense for either version, only the final
composite result.

Mark:
There isn't actually a bug here. regmap_config is always a valid
pointer in the current code. The later NULL check is currently
redundant.

I suggest (to avoid the confusion of which Fixes: SHA it
should reference) this is just added to for-next as a cleanup (not a
Fixes), since there's no bug.

> Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
> ---
>   sound/soc/codecs/cs35l56-shared-test.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/sound/soc/codecs/cs35l56-shared-test.c b/sound/soc/codecs/cs35l56-shared-test.c
> index 5b2b915559a9..4f52c8a192e5 100644
> --- a/sound/soc/codecs/cs35l56-shared-test.c
> +++ b/sound/soc/codecs/cs35l56-shared-test.c
> @@ -662,7 +662,6 @@ static int cs35l56_shared_test_case_base_init(struct kunit *test, u8 type, u8 re
>   
>   	test->priv = priv;
>   	priv->test = test;
> -	priv->reg_offset = regmap_config->reg_base;
>   
>   	/* Create dummy amp driver dev */
>   	priv->amp_dev = faux_device_create("cs35l56_shared_test_drv", NULL, NULL);

Re: [PATCH] ASoC: cs35l56-shared-test: Fix possible null pointer dereference

[Mark Brown]

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On Mon, May 25, 2026 at 10:49:03AM +0100, Richard Fitzgerald wrote:

> patch series. It turns out that V3 was already merged, but I didn't
> receive a merge notificiation. V4 has then been merged on top so Mark's
> for-7.2 and for-next contain the combination of V3 and V4 but this
> fix commit doesn't make sense for either version, only the final
> composite result.

You'll only get a notification for the most current version with my
current tooling (people complained about getting notifications on old
versions...) and if you resend quickly things might already be in my CI.

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Re: [PATCH] ASoC: cs35l56-shared-test: Fix possible null pointer dereference

[Mark Brown]

On Sat, 23 May 2026 16:15:22 -0500, Ethan Tidmore wrote:
> ASoC: cs35l56-shared-test: Fix possible null pointer dereference

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.2

Thanks!

[1/1] ASoC: cs35l56-shared-test: Fix possible null pointer dereference
      https://git.kernel.org/broonie/sound/c/4fa26292e8dc

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