[PATCH v2] ASoC: Intel: avs: Fix potential buffer overflow by snprintf()

From: hariconscious

Date: Wed Nov 12 2025 - 13:19:15 EST


From: HariKrishna Sagala <hariconscious@xxxxxxxxx>

snprintf() returns the would-be-filled size when the string overflows
the given buffer size, hence using this value may result in a buffer
overflow (although it's unrealistic).

This patch replaces it with a safer version, scnprintf() for papering
over such a potential issue.
Link: https://github.com/KSPP/linux/issues/105
'Fixes: 5a565ba23abe ("ASoC: Intel: avs: Probing and firmware tracing
over debugfs")'

Signed-off-by: HariKrishna Sagala <hariconscious@xxxxxxxxx>
---
Thank you for the feedback and the suggestions.
Corrected the indentation & commit message.
V1:
https://lore.kernel.org/all/20251112120235.54328-2-hariconscious@xxxxxxxxx/
sound/soc/intel/avs/debugfs.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/soc/intel/avs/debugfs.c b/sound/soc/intel/avs/debugfs.c
index 3534de46f9e4..cdb82392b9ee 100644
--- a/sound/soc/intel/avs/debugfs.c
+++ b/sound/soc/intel/avs/debugfs.c
@@ -119,9 +119,9 @@ static ssize_t probe_points_read(struct file *file, char __user *to, size_t coun
}

for (i = 0; i < num_desc; i++) {
- ret = snprintf(buf + len, PAGE_SIZE - len,
- "Id: %#010x Purpose: %d Node id: %#x\n",
- desc[i].id.value, desc[i].purpose, desc[i].node_id.val);
+ ret = scnprintf(buf + len, PAGE_SIZE - len,
+ "Id: %#010x Purpose: %d Node id: %#x\n",
+ desc[i].id.value, desc[i].purpose, desc[i].node_id.val);
if (ret < 0)
goto free_desc;
len += ret;

base-commit: 24172e0d79900908cf5ebf366600616d29c9b417
--
2.43.0