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| author | Takashi Iwai <tiwai@suse.de> | 2015-08-26 08:22:49 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2015-08-26 08:43:47 +0300 |
| commit | a92d5ee8666afcb4abc7686d7b760f0fb7a0c14c (patch) | |
| tree | 416230268de6d2d4017974c3f8f5656ded436f81 | |
| parent | 654e2751c9f00491c4622893de59a21784e39ccf (diff) | |
| download | linux-a92d5ee8666afcb4abc7686d7b760f0fb7a0c14c.tar.xz | |
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>
| -rw-r--r-- | sound/hda/hdac_device.c | 14 | ||||
| -rw-r--r-- | sound/hda/hdac_sysfs.c | 3 |
2 files changed, 11 insertions, 6 deletions
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c index aa6d6cec2380..db96042a497f 100644 --- a/sound/hda/hdac_device.c +++ b/sound/hda/hdac_device.c @@ -384,18 +384,20 @@ int snd_hdac_refresh_widget_sysfs(struct hdac_device *codec) { 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); diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c index 089b35f6f108..c71142dea98a 100644 --- a/sound/hda/hdac_sysfs.c +++ b/sound/hda/hdac_sysfs.c @@ -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); |