[PATCH] ALSA: asihpi: use scnprintf() for control name formatting

[Pengpeng Hou]

asihpi_ctl_init() builds mixer control names in the fixed 44-byte
hpi_ctl->name buffer with sprintf().

This is not only a defensive cleanup. The current in-tree name tables and
format strings can already exceed 44 bytes. For example,

  "Bitstream 0 Internal 0 Monitor Playback Volume"

is 46 characters before the trailing NUL, so the current sprintf() call
writes past the end of hpi_ctl->name.

Switch the formatting to scnprintf() so the driver truncates control
names instead of overflowing the fixed ALSA control name storage.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
 sound/pci/asihpi/asihpi.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/sound/pci/asihpi/asihpi.c b/sound/pci/asihpi/asihpi.c
index 3a64d0562803..de2859eb3e9f 100644
--- a/sound/pci/asihpi/asihpi.c
+++ b/sound/pci/asihpi/asihpi.c
@@ -1384,22 +1384,25 @@ static void asihpi_ctl_init(struct snd_kcontrol_new *snd_control,
 		dir = "Playback "; /* PCM Playback source, or  output node */
 
 	if (hpi_ctl->src_node_type && hpi_ctl->dst_node_type)
-		sprintf(hpi_ctl->name, "%s %d %s %d %s%s",
-			asihpi_src_names[hpi_ctl->src_node_type],
-			hpi_ctl->src_node_index,
-			asihpi_dst_names[hpi_ctl->dst_node_type],
-			hpi_ctl->dst_node_index,
-			dir, name);
+		scnprintf(hpi_ctl->name, sizeof(hpi_ctl->name),
+			  "%s %d %s %d %s%s",
+			  asihpi_src_names[hpi_ctl->src_node_type],
+			  hpi_ctl->src_node_index,
+			  asihpi_dst_names[hpi_ctl->dst_node_type],
+			  hpi_ctl->dst_node_index,
+			  dir, name);
 	else if (hpi_ctl->dst_node_type) {
-		sprintf(hpi_ctl->name, "%s %d %s%s",
-		asihpi_dst_names[hpi_ctl->dst_node_type],
-		hpi_ctl->dst_node_index,
-		dir, name);
+		scnprintf(hpi_ctl->name, sizeof(hpi_ctl->name),
+			  "%s %d %s%s",
+			  asihpi_dst_names[hpi_ctl->dst_node_type],
+			  hpi_ctl->dst_node_index,
+			  dir, name);
 	} else {
-		sprintf(hpi_ctl->name, "%s %d %s%s",
-		asihpi_src_names[hpi_ctl->src_node_type],
-		hpi_ctl->src_node_index,
-		dir, name);
+		scnprintf(hpi_ctl->name, sizeof(hpi_ctl->name),
+			  "%s %d %s%s",
+			  asihpi_src_names[hpi_ctl->src_node_type],
+			  hpi_ctl->src_node_index,
+			  dir, name);
 	}
 }
 
-- 
2.50.1 (Apple Git-155)