[PATCH v2] ASoC: SOF: validate topology volume range before allocation

SOF treats the topology mixer min and max values as non-negative indices
into its volume table. It stores them in signed fields, allocates max + 1
entries through an int argument, and later indexes the table with the
stored range.

An inverted range is invalid, while a maximum at or above INT_MAX cannot
be represented safely after the increment or in the signed fields.
Validate the complete range before storing it or allocating the table.

Fixes: 311ce4fe7637 ("ASoC: SOF: Add support for loading topologies")
Assisted-by: Codex:gpt-5
Signed-off-by: Pengpeng Hou <[email protected]>
---
Changes since v1: https://lore.kernel.org/all/[email protected]/
- validate SOF's non-negative table-index range before signed storage
- require max + 1 to remain representable by the allocator's int argument
- rebase on current SOF topology sources

The SOF table-index consumers and allocator conversion were reviewed
statically; no SOF topology or hardware test was performed.

 sound/soc/sof/topology.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/sound/soc/sof/topology.c b/sound/soc/sof/topology.c
index 42a2d90bb705..31dd7a66a9cf 100644
--- a/sound/soc/sof/topology.c
+++ b/sound/soc/sof/topology.c
@@ -846,6 +846,7 @@ static int sof_control_load_volume(struct snd_soc_component *scomp,
 	struct snd_soc_tplg_mixer_control *mc =
 		container_of(hdr, struct snd_soc_tplg_mixer_control, hdr);
 	int tlv[SOF_TLV_ITEMS];
+	u32 min, max;
 	unsigned int mask;
 	int ret;
 
@@ -853,6 +854,11 @@ static int sof_control_load_volume(struct snd_soc_component *scomp,
 	if (le32_to_cpu(mc->num_channels) > SND_SOC_TPLG_MAX_CHAN)
 		return -EINVAL;
 
+	min = le32_to_cpu(mc->min);
+	max = le32_to_cpu(mc->max);
+	if (min > max || max >= INT_MAX)
+		return -EINVAL;
+
 	/*
 	 * If control has more than 2 channels we need to override the info. This is because even if
 	 * ASoC layer has defined topology's max channel count to SND_SOC_TPLG_MAX_CHAN = 8, the
@@ -863,12 +869,12 @@ static int sof_control_load_volume(struct snd_soc_component *scomp,
 		kc->info = snd_sof_volume_info;
 
 	scontrol->comp_id = sdev->next_comp_id;
-	scontrol->min_volume_step = le32_to_cpu(mc->min);
-	scontrol->max_volume_step = le32_to_cpu(mc->max);
+	scontrol->min_volume_step = min;
+	scontrol->max_volume_step = max;
 	scontrol->num_channels = le32_to_cpu(mc->num_channels);
 
-	scontrol->max = le32_to_cpu(mc->max);
-	if (le32_to_cpu(mc->max) == 1)
+	scontrol->max = max;
+	if (max == 1)
 		goto skip;
 
 	/* extract tlv data */
@@ -878,7 +884,7 @@ static int sof_control_load_volume(struct snd_soc_component *scomp,
 	}
 
 	/* set up volume table */
-	ret = set_up_volume_table(scontrol, tlv, le32_to_cpu(mc->max) + 1);
+	ret = set_up_volume_table(scontrol, tlv, max + 1);
 	if (ret < 0) {
 		dev_err(scomp->dev, "error: setting up volume table\n");
 		return ret;
@@ -911,7 +917,7 @@ static int sof_control_load_volume(struct snd_soc_component *scomp,
 	return 0;
 
 err:
-	if (le32_to_cpu(mc->max) > 1)
+	if (max > 1)
 		kfree(scontrol->volume_table);
 
 	return ret;
-- 
2.50.1 (Apple Git-155)