From: Jaroslav Kysela <perex@perex.cz>
Date: Thu, 29 Jan 2026 15:51:09 +0000 (+0100)
Subject: topology: decoder - add boundary check for channel mixer count
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=5f7fe33002d2d98d84f72e381ec2cccc0d5d3d40;p=alsa-lib.git

topology: decoder - add boundary check for channel mixer count

Malicious binary topology file may cause heap corruption.

CVE: CVE-2026-25068

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---

diff --git a/src/topology/ctl.c b/src/topology/ctl.c
index a0c24518..322c461c 100644
--- a/src/topology/ctl.c
+++ b/src/topology/ctl.c
@@ -1250,6 +1250,11 @@ int tplg_decode_control_mixer1(snd_tplg_t *tplg,
 	if (mc->num_channels > 0) {
 		map = tplg_calloc(heap, sizeof(*map));
 		map->num_channels = mc->num_channels;
+		if (map->num_channels > SND_TPLG_MAX_CHAN ||
+		    map->num_channels > SND_SOC_TPLG_MAX_CHAN) {
+			snd_error(TOPOLOGY, "mixer: unexpected channel count %d", map->num_channels);
+			return -EINVAL;
+		}
 		for (i = 0; i < map->num_channels; i++) {
 			map->channel[i].reg = mc->channel[i].reg;
 			map->channel[i].shift = mc->channel[i].shift;