ALSA: control: Avoid WARN() for symlink errors

Using WARN() for showing the error of symlink creations don't give
more information than telling that something goes wrong, since the
usual code path is a lregister callback from each control element
creation.  More badly, the use of WARN() rather confuses fuzzer as if
it were serious issues.

This patch downgrades the warning messages to use the normal dev_err()
instead of WARN().  For making it clearer, add the function name to
the prefix, too.

Fixes: a135dfb5de15 ("ALSA: led control - add sysfs kcontrol LED marking layer")
Reported-by: syzbot+4e7919b09c67ffd198ae@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/675664c7.050a0220.a30f1.018c.GAE@google.com
Link: https://patch.msgid.link/20241209095614.4273-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index 65a1ebe877768f1aa4a6e83c00658656488376d2..e33dfcf863cf13f4e41987d1ed2d28540b745fac 100644 (file)
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -668,10 +668,16 @@ static void snd_ctl_led_sysfs_add(struct snd_card *card)
                        goto cerr;
                led->cards[card->number] = led_card;
                snprintf(link_name, sizeof(link_name), "led-%s", led->name);
-               WARN(sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj, link_name),
-                       "can't create symlink to controlC%i device\n", card->number);
-               WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"),
-                       "can't create symlink to card%i\n", card->number);
+               if (sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj,
+                                     link_name))
+                       dev_err(card->dev,
+                               "%s: can't create symlink to controlC%i device\n",
+                                __func__, card->number);
+               if (sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj,
+                                     "card"))
+                       dev_err(card->dev,
+                               "%s: can't create symlink to card%i\n",
+                               __func__, card->number);
 
                continue;
 cerr: