current/SOURCES/alsa-control-led-use-strscpy-in-set_led_id.patch

From 70051cffb31b5ee09096351c3b41fcae6f89de31 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Mon, 9 Jan 2023 16:12:49 +0100
Subject: ALSA: control-led: use strscpy in set_led_id()

From: Jaroslav Kysela <perex@perex.cz>

commit 70051cffb31b5ee09096351c3b41fcae6f89de31 upstream.

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/core/control_led.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- 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
                          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;
1	From 70051cffb31b5ee09096351c3b41fcae6f89de31 Mon Sep 17 00:00:00 2001
2	From: Jaroslav Kysela <perex@perex.cz>
3	Date: Mon, 9 Jan 2023 16:12:49 +0100
4	Subject: ALSA: control-led: use strscpy in set_led_id()
5
6	From: Jaroslav Kysela <perex@perex.cz>
7
8	commit 70051cffb31b5ee09096351c3b41fcae6f89de31 upstream.
9
10	The use of strncpy() in the set_led_id() was incorrect.
11	The len variable should use 'min(sizeof(buf2) - 1, count)'
12	expression.
13
14	Use strscpy() function to simplify things and handle the error gracefully.
15
16	Fixes: a135dfb5de15 ("ALSA: led control - add sysfs kcontrol LED marking layer")
17	Reported-by: yang.yang29@zte.com.cn
18	Link: https://lore.kernel.org/alsa-devel/202301091945513559977@zte.com.cn/
19	Cc: <stable@vger.kernel.org>
20	Signed-off-by: Jaroslav Kysela <perex@perex.cz>
21	Signed-off-by: Takashi Iwai <tiwai@suse.de>
22	Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
23	---
24	sound/core/control_led.c \| 5 ++---
25	1 file changed, 2 insertions(+), 3 deletions(-)
26
27	--- a/sound/core/control_led.c
28	+++ b/sound/core/control_led.c
29	@@ -530,12 +530,11 @@ static ssize_t set_led_id(struct snd_ctl
30	bool attach)
31	{
32	char buf2[256], s, os;
33	- size_t len = max(sizeof(s) - 1, count);
34	struct snd_ctl_elem_id id;
35	int err;
36
37	- strncpy(buf2, buf, len);
38	- buf2[len] = '\0';
39	+ if (strscpy(buf2, buf, sizeof(buf2)) < 0)
40	+ return -E2BIG;
41	memset(&id, 0, sizeof(id));
42	id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
43	s = buf2;