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authorTakashi Iwai <tiwai@suse.de>2015-08-26 07:22:49 +0200
committerTakashi Iwai <tiwai@suse.de>2015-08-26 07:43:47 +0200
commita92d5ee8666afcb4abc7686d7b760f0fb7a0c14c (patch)
tree416230268de6d2d4017974c3f8f5656ded436f81 /sound/hda/hdac_sysfs.c
parent654e2751c9f00491c4622893de59a21784e39ccf (diff)
downloadlinux-a92d5ee8666afcb4abc7686d7b760f0fb7a0c14c.tar.bz2
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>
Diffstat (limited to 'sound/hda/hdac_sysfs.c')
-rw-r--r--sound/hda/hdac_sysfs.c3
1 files changed, 3 insertions, 0 deletions
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);