Affected: Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

HID: appletb-kbd: run inactivity autodim from workqueues

The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts:

* appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: <IRQ> __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq

* reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning.

Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue:

* Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal. * Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of c…

In the Linux kernel, the following vulnerability has been resolved:

HID: appletb-kbd: run inactivity autodim from workqueues

The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts:

* appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: <IRQ> __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq

* reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning.

Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue:

* Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal. * Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of c…

kernel-devel-7.0.11-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 124 more

In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: run inactivity autodim from workqueues The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts: * appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: <IRQ> __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq * reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning. Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue: * Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal. * Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of calling…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder andere nicht näher spezifizierte Auswirkungen zu erzielen.