ALSA: hda - Fix widget sysfs tree corruption after refresh (a92d5ee8) · Commits · 戴 / test

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: ('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>

sound/hda/hdac_device.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -384,18 +384,20 @@ int snd_hdac_refresh_widget_sysfs(struct hdac_device *codec)
		{
		int ret;

		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;
		}
		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);

sound/hda/hdac_sysfs.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -390,6 +390,9 @@ int hda_widget_sysfs_init(struct hdac_device *codec)
		{
		int err;

		if (codec->widgets)
		return 0; /* already created */

		err = widget_tree_create(codec);
		if (err < 0) {
		widget_tree_free(codec);

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