ALSA: hda - Fix widget sysfs tree corruption after refresh
When snd_hdac_refresh_widget_sysfs() is called before the first
hda_widget_sysfs_init(), the next call overrides and eventually
fails. This results in unexpected Oops, something like:
BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8
IP: [<ffffffff8180e2a3>] hdmi_chmap_ctl_info+0x23/0x40
The fix is to add a check of the existing sysfs tree. Also, for more
safety, this patch adds the checks of device_is_registered() in
snd-hdac_refresh_wdiget_sysfs(), too.
Fixes: fa4f18b4f402 ('ALSA: hda - Refresh widgets sysfs at probing Haswell+ HDMI codecs')
Bugizlla: https://bugzilla.kernel.org/show_bug.cgi?id=103431
Reported-by: Andreas Reis <andreas.reis@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index aa6d6ce..db96042 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -384,18 +384,20 @@
{
int ret;
- hda_widget_sysfs_exit(codec);
+ if (device_is_registered(&codec->dev))
+ hda_widget_sysfs_exit(codec);
ret = snd_hdac_refresh_widgets(codec);
if (ret) {
dev_err(&codec->dev, "failed to refresh widget: %d\n", ret);
return ret;
}
- ret = hda_widget_sysfs_init(codec);
- if (ret) {
- dev_err(&codec->dev, "failed to init sysfs: %d\n", ret);
- return ret;
+ if (device_is_registered(&codec->dev)) {
+ ret = hda_widget_sysfs_init(codec);
+ if (ret) {
+ dev_err(&codec->dev, "failed to init sysfs: %d\n", ret);
+ return ret;
+ }
}
-
return ret;
}
EXPORT_SYMBOL_GPL(snd_hdac_refresh_widget_sysfs);