[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@xxxxxxxxx>
---
 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