hda_widget_sysfs_reinit() can free underlying codec->widgets structure on which widget_tree_create() operates. Add locking to prevent such issues from happening.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110382 Signed-off-by: Amadeusz Sławiński amadeuszx.slawinski@linux.intel.com ---

Changes since v1: - Moved mutexes around the callers - Added comments noting that functions should be called with mutex held

--- include/sound/hdaudio.h | 1 + sound/hda/hdac_device.c | 7 +++++++ sound/hda/hdac_sysfs.c | 3 +++ 3 files changed, 11 insertions(+)

diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index 45f944d57982..85835d0c33cc 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -81,6 +81,7 @@ struct hdac_device { atomic_t in_pm; /* suspend/resume being performed */

/* sysfs */ + struct mutex widget_lock; struct hdac_widget_tree *widgets;

/* regmap */ diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c index 95b073ee4b32..4769f4c03e14 100644 --- a/sound/hda/hdac_device.c +++ b/sound/hda/hdac_device.c @@ -55,6 +55,7 @@ int snd_hdac_device_init(struct hdac_device *codec, struct hdac_bus *bus, codec->bus = bus; codec->addr = addr; codec->type = HDA_DEV_CORE; + mutex_init(&codec->widget_lock); pm_runtime_set_active(&codec->dev); pm_runtime_get_noresume(&codec->dev); atomic_set(&codec->in_pm, 0); @@ -141,7 +142,9 @@ int snd_hdac_device_register(struct hdac_device *codec) err = device_add(&codec->dev); if (err < 0) return err; + mutex_lock(&codec->widget_lock); err = hda_widget_sysfs_init(codec); + mutex_unlock(&codec->widget_lock); if (err < 0) { device_del(&codec->dev); return err; @@ -158,7 +161,9 @@ EXPORT_SYMBOL_GPL(snd_hdac_device_register); void snd_hdac_device_unregister(struct hdac_device *codec) { if (device_is_registered(&codec->dev)) { + mutex_lock(&codec->widget_lock); hda_widget_sysfs_exit(codec); + mutex_unlock(&codec->widget_lock); device_del(&codec->dev); snd_hdac_bus_remove_device(codec->bus, codec); } @@ -404,7 +409,9 @@ int snd_hdac_refresh_widgets(struct hdac_device *codec, bool sysfs) }

if (sysfs) { + mutex_lock(&codec->widget_lock); err = hda_widget_sysfs_reinit(codec, start_nid, nums); + mutex_unlock(&codec->widget_lock); if (err < 0) return err; } diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c index fb2aa344981e..909d5ef1179c 100644 --- a/sound/hda/hdac_sysfs.c +++ b/sound/hda/hdac_sysfs.c @@ -395,6 +395,7 @@ static int widget_tree_create(struct hdac_device *codec) return 0; }

+/* call with codec->widget_lock held */ int hda_widget_sysfs_init(struct hdac_device *codec) { int err; @@ -411,11 +412,13 @@ int hda_widget_sysfs_init(struct hdac_device *codec) return 0; }

+/* call with codec->widget_lock held */ void hda_widget_sysfs_exit(struct hdac_device *codec) { widget_tree_free(codec); }

+/* call with codec->widget_lock held */ int hda_widget_sysfs_reinit(struct hdac_device *codec, hda_nid_t start_nid, int num_nodes) {