[PATCH] ASoC: dapm: Fix off-by-one check on the second enum channel

[PATCH] ASoC: dapm: Fix off-by-one check on the second enum channel

[HyeongJun An]

The snd_soc_dapm_put_enum_double() rejects item[0] once it reaches
e->items, but it lets item[1] be equal to it.  Both go on to
snd_soc_enum_item_to_val(), which indexes e->values with no bound of
its own, so an enum with a value table reads one element past the end.

The indexing arrived with the MUX consolidation, which relaxed the
item[1] check in the same hunk.  The value MUX handler it deleted used
>= there, and the snd_soc_put_enum_double() in soc-ops.c still does.

Only adav80x pairs a value table with two shifts, and its second
channel looks accidental, but the control does report two values.
Writing three into it reads off the end of adav80x_mux_values.  The
core catches that only under CONFIG_SND_CTL_INPUT_VALIDATION, which
defaults off.

Fixes: 3727b4968453 ("ASoC: dapm: Consolidate MUXs and value MUXs")
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
---
 sound/soc/soc-dapm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index c98e917cc911..06b85313af12 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -3614,7 +3614,7 @@ int snd_soc_dapm_put_enum_double(struct snd_kcontrol *kcontrol,
 	val = snd_soc_enum_item_to_val(e, item[0]) << e->shift_l;
 	mask = e->mask << e->shift_l;
 	if (e->shift_l != e->shift_r) {
-		if (item[1] > e->items)
+		if (item[1] >= e->items)
 			return -EINVAL;
 		val |= snd_soc_enum_item_to_val(e, item[1]) << e->shift_r;
 		mask |= e->mask << e->shift_r;
-- 
2.43.0

Re: [PATCH] ASoC: dapm: Fix off-by-one check on the second enum channel

[Mark Brown]

On Tue, 25 Aug 2026 21:57:45 +0900, HyeongJun An wrote:
> ASoC: dapm: Fix off-by-one check on the second enum channel

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.3

Thanks!

[1/1] ASoC: dapm: Fix off-by-one check on the second enum channel
      https://git.kernel.org/broonie/sound/c/14511c9b54ce

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