[PATCH] ALSA: hda: cs35l56: Fix uninitialized value in cs35l56_hda_read_acpi()

[PATCH] ALSA: hda: cs35l56: Fix uninitialized value in cs35l56_hda_read_acpi()

[Richard Fitzgerald]

Eliminate the uninitialized 'nval' in cs35l56_hda_read_acpi() if a
system-specific quirk overrides processing of the dev-index property.
The value is now stored in a new 'num_amps' member of struct cs35l56_hda
so that the quirk handler can set the value.

The quirk for the Lenovo Yoga Book 9i GenX  replaces the values from the
dev-index property with hardcoded indexes. So cs35l56_hda_read_acpi() would
then skip reading the property. But this left the 'nval' local variable
uninitialized when it is later passed to cirrus_scodec_get_speaker_id().

Fixes: 40b1c2f9b299 ("ALSA: hda/cs35l56: Workaround bad dev-index on Lenovo Yoga Book 9i GenX")
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/linux-sound/aenFesLAStjrVNy8@stanley.mountain/T/#u
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/hda/codecs/side-codecs/cs35l56_hda.c | 12 +++++++-----
 sound/hda/codecs/side-codecs/cs35l56_hda.h |  1 +
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/hda/codecs/side-codecs/cs35l56_hda.c b/sound/hda/codecs/side-codecs/cs35l56_hda.c
index dc25960a4f23..4c8d01799931 100644
--- a/sound/hda/codecs/side-codecs/cs35l56_hda.c
+++ b/sound/hda/codecs/side-codecs/cs35l56_hda.c
@@ -976,6 +976,7 @@ static int cs35l56_hda_system_resume(struct device *dev)
 static int cs35l56_hda_fixup_yoga9(struct cs35l56_hda *cs35l56, int *bus_addr)
 {
 	/* The cirrus,dev-index property has the wrong values */
+	cs35l56->num_amps = 2;
 	switch (*bus_addr) {
 	case 0x30:
 		cs35l56->index = 1;
@@ -1025,7 +1026,6 @@ static int cs35l56_hda_read_acpi(struct cs35l56_hda *cs35l56, int hid, int id)
 	char hid_string[8];
 	struct acpi_device *adev;
 	const char *property, *sub;
-	size_t nval;
 	int i, ret;
 
 	/*
@@ -1061,13 +1061,14 @@ static int cs35l56_hda_read_acpi(struct cs35l56_hda *cs35l56, int hid, int id)
 			ret = -EINVAL;
 			goto err;
 		}
-		nval = ret;
+		cs35l56->num_amps = ret;
 
-		ret = device_property_read_u32_array(cs35l56->base.dev, property, values, nval);
+		ret = device_property_read_u32_array(cs35l56->base.dev, property, values,
+						     cs35l56->num_amps);
 		if (ret)
 			goto err;
 
-		for (i = 0; i < nval; i++) {
+		for (i = 0; i < cs35l56->num_amps; i++) {
 			if (values[i] == id) {
 				cs35l56->index = i;
 				break;
@@ -1090,7 +1091,8 @@ static int cs35l56_hda_read_acpi(struct cs35l56_hda *cs35l56, int hid, int id)
 			 "Read ACPI _SUB failed(%ld): fallback to generic firmware\n",
 			 PTR_ERR(sub));
 	} else {
-		ret = cirrus_scodec_get_speaker_id(cs35l56->base.dev, cs35l56->index, nval, -1);
+		ret = cirrus_scodec_get_speaker_id(cs35l56->base.dev, cs35l56->index,
+						   cs35l56->num_amps, -1);
 		if (ret == -ENOENT) {
 			cs35l56->system_name = sub;
 		} else if (ret >= 0) {
diff --git a/sound/hda/codecs/side-codecs/cs35l56_hda.h b/sound/hda/codecs/side-codecs/cs35l56_hda.h
index cb4b5e7356a3..3705af7c186b 100644
--- a/sound/hda/codecs/side-codecs/cs35l56_hda.h
+++ b/sound/hda/codecs/side-codecs/cs35l56_hda.h
@@ -26,6 +26,7 @@ struct cs35l56_hda {
 	struct work_struct dsp_work;
 
 	int index;
+	int num_amps;
 	const char *system_name;
 	const char *amp_name;
 
-- 
2.47.3

Re: [PATCH] ALSA: hda: cs35l56: Fix uninitialized value in cs35l56_hda_read_acpi()

[Takashi Iwai]

On Tue, 28 Apr 2026 15:05:31 +0200,
Richard Fitzgerald wrote:
> 
> Eliminate the uninitialized 'nval' in cs35l56_hda_read_acpi() if a
> system-specific quirk overrides processing of the dev-index property.
> The value is now stored in a new 'num_amps' member of struct cs35l56_hda
> so that the quirk handler can set the value.
> 
> The quirk for the Lenovo Yoga Book 9i GenX  replaces the values from the
> dev-index property with hardcoded indexes. So cs35l56_hda_read_acpi() would
> then skip reading the property. But this left the 'nval' local variable
> uninitialized when it is later passed to cirrus_scodec_get_speaker_id().
> 
> Fixes: 40b1c2f9b299 ("ALSA: hda/cs35l56: Workaround bad dev-index on Lenovo Yoga Book 9i GenX")
> Reported-by: Dan Carpenter <error27@gmail.com>
> Closes: https://lore.kernel.org/linux-sound/aenFesLAStjrVNy8@stanley.mountain/T/#u
> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>

Applied now.  Thanks.


Takashi