diff mbox series

[v3] ALSA: control-led: use strscpy in set_led_id()

Message ID 20230109151249.343741-1-perex@perex.cz (mailing list archive)
State New, archived
Headers show
Series [v3] ALSA: control-led: use strscpy in set_led_id() | expand

Commit Message

Jaroslav Kysela Jan. 9, 2023, 3:12 p.m. UTC
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(-)

Comments

Takashi Iwai Jan. 9, 2023, 4:04 p.m. UTC | #1
On Mon, 09 Jan 2023 16:12:49 +0100,
Jaroslav Kysela wrote:
> 
> 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

Thanks, applied.


Takashi
diff mbox series

Patch

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;