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@zte.com.cn Link: https://lore.kernel.org/alsa-devel/202301091945513559977@zte.com.cn/ Cc: stable@vger.kernel.org Signed-off-by: Jaroslav Kysela perex@perex.cz

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;