The use of strncpy() in the set_led_id() was incorrect.
The len variable should use 'min(sizeof(buf2) - 1, count)'
expression.
Use strscpy() function to simplify things and handle the error gracefully.
Fixes: a135dfb5de15 ("ALSA: led control - add sysfs kcontrol LED marking layer")
Reported-by: yang.yang29@xxxxxxxxxx
Link: https://lore.kernel.org/alsa-devel/202301091945513559977@xxxxxxxxxx/
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jaroslav Kysela <perex@xxxxxxxx>
v1..v2:
- remove min() expression which strips the last char
v2..v3:
- BugLink -> Link
- add Fixes tag
---
sound/core/control_led.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index f975cc85772b..3cadd40100f3 100644
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -530,12 +530,11 @@ static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, si
bool attach)
{
char buf2[256], *s, *os;
- size_t len = max(sizeof(s) - 1, count);
struct snd_ctl_elem_id id;
int err;
- strncpy(buf2, buf, len);
- buf2[len] = '\0';
+ if (strscpy(buf2, buf, sizeof(buf2)) < 0)
+ return -E2BIG;
memset(&id, 0, sizeof(id));
id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
s = buf2;
--
2.39.0
