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
backlight_device_set_brightness() directly.
Cancel both works synchronously during driver tear-down alongside the
existing backlight reference drop.
The semantics are unchanged (same delays, same state transitions on
dim, turn-off and user activity); only the execution context of the
sleeping call changes. The timer field and callback are renamed to
match their new type; reset_inactivity_timer() keeps its name because
it is invoked from input event paths that read naturally as "reset
the inactivity timer".
Fixes: 93a0fc4894 ("HID: hid-appletb-kbd: add support for automatic brightness control while using the touchbar")
Cc: stable@vger.kernel.org
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Commit 38224c472a ("HID: appletb-kbd: fix slab use-after-free bug in
appletb_kbd_probe") added timer_delete_sync(&kbd->inactivity_timer) to
both the probe close_hw error path and appletb_kbd_remove(), but the
way it was wired in left the inactivity timer reachable during driver
tear-down via two distinct windows.
Window A -- put_device() before timer_delete_sync():
put_device(&kbd->backlight_dev->dev);
timer_delete_sync(&kbd->inactivity_timer);
The inactivity_timer softirq reads kbd->backlight_dev and calls
backlight_device_set_brightness() -> mutex_lock(&ops_lock). If a
concurrent hid_appletb_bl unbind drops the last devm reference
between these two calls, the backlight_device is freed and the
mutex_lock() touches freed memory.
Window B -- backlight cleanup before hid_hw_stop():
if (kbd->backlight_dev) {
timer_delete_sync(...);
put_device(...);
}
hid_hw_close(hdev);
hid_hw_stop(hdev);
Even after Window A is closed, hid_hw_close()/hid_hw_stop() still run
afterwards, so a late ".event" callback from the HID core (USB URB
completion on real Apple hardware) can arrive after
timer_delete_sync() drained the softirq but before put_device() drops
the reference. That callback reaches reset_inactivity_timer(), which
calls mod_timer() and re-arms the timer. The freshly re-armed timer
can then fire on the about-to-be-freed backlight_device.
Both windows produce the same KASAN slab-use-after-free:
BUG: KASAN: slab-use-after-free in __mutex_lock+0x1aab/0x21c0
Read of size 8 at addr ffff88803ee9a108 by task swapper/0/0
Call Trace:
<IRQ>
__mutex_lock
backlight_device_set_brightness
appletb_inactivity_timer
call_timer_fn
run_timer_softirq
handle_softirqs
Allocated by task N:
devm_backlight_device_register
appletb_bl_probe
Freed by task M:
(concurrent hid_appletb_bl unbind path)
Close both windows at once by reworking the tear-down in
appletb_kbd_remove() and in the probe close_hw error path so that
1) hid_hw_close()/hid_hw_stop() run before the backlight cleanup,
guaranteeing no further .event callback can fire and re-arm the
timer, and
2) inside the "if (kbd->backlight_dev)" block, timer_delete_sync()
runs before put_device(), so the softirq is drained before the
final reference is dropped.
Fixes: 38224c472a ("HID: appletb-kbd: fix slab use-after-free bug in appletb_kbd_probe")
Cc: stable@vger.kernel.org
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Upon resuming from suspend, the Touch Bar driver was missing a resume
method in order to restore the original mode the Touch Bar was on before
suspending. It is the same as the reset_resume method.
[jkosina@suse.com: rebased on top of the pm_ptr() conversion]
Cc: stable@vger.kernel.org
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This increases build coverage and allows to drop an #ifdef.
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
In probe appletb_kbd_probe() a "struct appletb_kbd *kbd" is allocated
via devm_kzalloc() to store touch bar keyboard related data.
Later on if backlight_device_get_by_name() finds a backlight device
with name "appletb_backlight" a timer (kbd->inactivity_timer) is setup
with appletb_inactivity_timer() and the timer is armed to run after
appletb_tb_dim_timeout (60) seconds.
A use-after-free is triggered when failure occurs after the timer is
armed. This ultimately means probe failure occurs and as a result the
"struct appletb_kbd *kbd" which is device managed memory is freed.
After 60 seconds the timer will have expired and __run_timers will
attempt to access the timer (kbd->inactivity_timer) however the kdb
structure has been freed causing a use-after free.
[ 71.636938] ==================================================================
[ 71.637915] BUG: KASAN: slab-use-after-free in __run_timers+0x7ad/0x890
[ 71.637915] Write of size 8 at addr ffff8881178c5958 by task swapper/1/0
[ 71.637915]
[ 71.637915] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc2-00318-g739a6c93cc75-dirty #12 PREEMPT(voluntary)
[ 71.637915] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 71.637915] Call Trace:
[ 71.637915] <IRQ>
[ 71.637915] dump_stack_lvl+0x53/0x70
[ 71.637915] print_report+0xce/0x670
[ 71.637915] ? __run_timers+0x7ad/0x890
[ 71.637915] kasan_report+0xce/0x100
[ 71.637915] ? __run_timers+0x7ad/0x890
[ 71.637915] __run_timers+0x7ad/0x890
[ 71.637915] ? __pfx___run_timers+0x10/0x10
[ 71.637915] ? update_process_times+0xfc/0x190
[ 71.637915] ? __pfx_update_process_times+0x10/0x10
[ 71.637915] ? _raw_spin_lock_irq+0x80/0xe0
[ 71.637915] ? _raw_spin_lock_irq+0x80/0xe0
[ 71.637915] ? __pfx__raw_spin_lock_irq+0x10/0x10
[ 71.637915] run_timer_softirq+0x141/0x240
[ 71.637915] ? __pfx_run_timer_softirq+0x10/0x10
[ 71.637915] ? __pfx___hrtimer_run_queues+0x10/0x10
[ 71.637915] ? kvm_clock_get_cycles+0x18/0x30
[ 71.637915] ? ktime_get+0x60/0x140
[ 71.637915] handle_softirqs+0x1b8/0x5c0
[ 71.637915] ? __pfx_handle_softirqs+0x10/0x10
[ 71.637915] irq_exit_rcu+0xaf/0xe0
[ 71.637915] sysvec_apic_timer_interrupt+0x6c/0x80
[ 71.637915] </IRQ>
[ 71.637915]
[ 71.637915] Allocated by task 39:
[ 71.637915] kasan_save_stack+0x33/0x60
[ 71.637915] kasan_save_track+0x14/0x30
[ 71.637915] __kasan_kmalloc+0x8f/0xa0
[ 71.637915] __kmalloc_node_track_caller_noprof+0x195/0x420
[ 71.637915] devm_kmalloc+0x74/0x1e0
[ 71.637915] appletb_kbd_probe+0x37/0x3c0
[ 71.637915] hid_device_probe+0x2d1/0x680
[ 71.637915] really_probe+0x1c3/0x690
[ 71.637915] __driver_probe_device+0x247/0x300
[ 71.637915] driver_probe_device+0x49/0x210
[...]
[ 71.637915]
[ 71.637915] Freed by task 39:
[ 71.637915] kasan_save_stack+0x33/0x60
[ 71.637915] kasan_save_track+0x14/0x30
[ 71.637915] kasan_save_free_info+0x3b/0x60
[ 71.637915] __kasan_slab_free+0x37/0x50
[ 71.637915] kfree+0xcf/0x360
[ 71.637915] devres_release_group+0x1f8/0x3c0
[ 71.637915] hid_device_probe+0x315/0x680
[ 71.637915] really_probe+0x1c3/0x690
[ 71.637915] __driver_probe_device+0x247/0x300
[ 71.637915] driver_probe_device+0x49/0x210
[...]
The root cause of the issue is that the timer is not disarmed
on failure paths leading to it remaining active and accessing
freed memory. To fix this call timer_delete_sync() to deactivate
the timer.
Another small issue is that timer_delete_sync is called
unconditionally in appletb_kbd_remove(), fix this by checking
for a valid kbd->backlight_dev before calling timer_delete_sync.
Fixes: 93a0fc4894 ("HID: hid-appletb-kbd: add support for automatic brightness control while using the touchbar")
Cc: stable@vger.kernel.org
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
In appletb_kbd_probe an input handler is initialised and then registered
with input core through input_register_handler(). When this happens input
core will add the input handler (specifically its node) to the global
input_handler_list. The input_handler_list is central to the functionality
of input core and is traversed in various places in input core. An example
of this is when a new input device is plugged in and gets registered with
input core.
The input_handler in probe is allocated as device managed memory. If a
probe failure occurs after input_register_handler() the input_handler
memory is freed, yet it will remain in the input_handler_list. This
effectively means the input_handler_list contains a dangling pointer
to data belonging to a freed input handler.
This causes an issue when any other input device is plugged in - in my
case I had an old PixArt HP USB optical mouse and I decided to
plug it in after a failure occurred after input_register_handler().
This lead to the registration of this input device via
input_register_device which involves traversing over every handler
in the corrupted input_handler_list and calling input_attach_handler(),
giving each handler a chance to bind to newly registered device.
The core of this bug is a UAF which causes memory corruption of
input_handler_list and to fix it we must ensure the input handler is
unregistered from input core, this is done through
input_unregister_handler().
[ 63.191597] ==================================================================
[ 63.192094] BUG: KASAN: slab-use-after-free in input_attach_handler.isra.0+0x1a9/0x1e0
[ 63.192094] Read of size 8 at addr ffff888105ea7c80 by task kworker/0:2/54
[ 63.192094]
[ 63.192094] CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.16.0-rc2-00321-g2aa6621d
[ 63.192094] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.164
[ 63.192094] Workqueue: usb_hub_wq hub_event
[ 63.192094] Call Trace:
[ 63.192094] <TASK>
[ 63.192094] dump_stack_lvl+0x53/0x70
[ 63.192094] print_report+0xce/0x670
[ 63.192094] kasan_report+0xce/0x100
[ 63.192094] input_attach_handler.isra.0+0x1a9/0x1e0
[ 63.192094] input_register_device+0x76c/0xd00
[ 63.192094] hidinput_connect+0x686d/0xad60
[ 63.192094] hid_connect+0xf20/0x1b10
[ 63.192094] hid_hw_start+0x83/0x100
[ 63.192094] hid_device_probe+0x2d1/0x680
[ 63.192094] really_probe+0x1c3/0x690
[ 63.192094] __driver_probe_device+0x247/0x300
[ 63.192094] driver_probe_device+0x49/0x210
[ 63.192094] __device_attach_driver+0x160/0x320
[ 63.192094] bus_for_each_drv+0x10f/0x190
[ 63.192094] __device_attach+0x18e/0x370
[ 63.192094] bus_probe_device+0x123/0x170
[ 63.192094] device_add+0xd4d/0x1460
[ 63.192094] hid_add_device+0x30b/0x910
[ 63.192094] usbhid_probe+0x920/0xe00
[ 63.192094] usb_probe_interface+0x363/0x9a0
[ 63.192094] really_probe+0x1c3/0x690
[ 63.192094] __driver_probe_device+0x247/0x300
[ 63.192094] driver_probe_device+0x49/0x210
[ 63.192094] __device_attach_driver+0x160/0x320
[ 63.192094] bus_for_each_drv+0x10f/0x190
[ 63.192094] __device_attach+0x18e/0x370
[ 63.192094] bus_probe_device+0x123/0x170
[ 63.192094] device_add+0xd4d/0x1460
[ 63.192094] usb_set_configuration+0xd14/0x1880
[ 63.192094] usb_generic_driver_probe+0x78/0xb0
[ 63.192094] usb_probe_device+0xaa/0x2e0
[ 63.192094] really_probe+0x1c3/0x690
[ 63.192094] __driver_probe_device+0x247/0x300
[ 63.192094] driver_probe_device+0x49/0x210
[ 63.192094] __device_attach_driver+0x160/0x320
[ 63.192094] bus_for_each_drv+0x10f/0x190
[ 63.192094] __device_attach+0x18e/0x370
[ 63.192094] bus_probe_device+0x123/0x170
[ 63.192094] device_add+0xd4d/0x1460
[ 63.192094] usb_new_device+0x7b4/0x1000
[ 63.192094] hub_event+0x234d/0x3fa0
[ 63.192094] process_one_work+0x5bf/0xfe0
[ 63.192094] worker_thread+0x777/0x13a0
[ 63.192094] </TASK>
[ 63.192094]
[ 63.192094] Allocated by task 54:
[ 63.192094] kasan_save_stack+0x33/0x60
[ 63.192094] kasan_save_track+0x14/0x30
[ 63.192094] __kasan_kmalloc+0x8f/0xa0
[ 63.192094] __kmalloc_node_track_caller_noprof+0x195/0x420
[ 63.192094] devm_kmalloc+0x74/0x1e0
[ 63.192094] appletb_kbd_probe+0x39/0x440
[ 63.192094] hid_device_probe+0x2d1/0x680
[ 63.192094] really_probe+0x1c3/0x690
[ 63.192094] __driver_probe_device+0x247/0x300
[ 63.192094] driver_probe_device+0x49/0x210
[ 63.192094] __device_attach_driver+0x160/0x320
[...]
[ 63.192094]
[ 63.192094] Freed by task 54:
[ 63.192094] kasan_save_stack+0x33/0x60
[ 63.192094] kasan_save_track+0x14/0x30
[ 63.192094] kasan_save_free_info+0x3b/0x60
[ 63.192094] __kasan_slab_free+0x37/0x50
[ 63.192094] kfree+0xcf/0x360
[ 63.192094] devres_release_group+0x1f8/0x3c0
[ 63.192094] hid_device_probe+0x315/0x680
[ 63.192094] really_probe+0x1c3/0x690
[ 63.192094] __driver_probe_device+0x247/0x300
[ 63.192094] driver_probe_device+0x49/0x210
[ 63.192094] __device_attach_driver+0x160/0x320
[...]
Fixes: 7d62ba8dea ("HID: hid-appletb-kbd: add support for fn toggle between media and function mode")
Cc: stable@vger.kernel.org
Reviewed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
During appletb_kbd_probe, probe attempts to get the backlight device
by name. When this happens backlight_device_get_by_name looks for a
device in the backlight class which has name "appletb_backlight" and
upon finding a match it increments the reference count for the device
and returns it to the caller. However this reference is never released
leading to a reference leak.
Fix this by decrementing the backlight device reference count on removal
via put_device and on probe failure.
Fixes: 93a0fc4894 ("HID: hid-appletb-kbd: add support for automatic brightness control while using the touchbar")
Cc: stable@vger.kernel.org
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
-----BEGIN PGP SIGNATURE-----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=qI/U
-----END PGP SIGNATURE-----
Merge tag 'hid-for-linus-2025060301' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid
Pull HID updates from Jiri Kosina:
- support for Apple Magic Mouse 2 USB-C (Aditya Garg)
- power management improvement for multitouch devices (Werner Sembach)
- fix for ACPI initialization in intel-thc driver (Wentao Guan)
- adaptation of HID drivers to use new gpio_chip's line setter
callbacks (Bartosz Golaszewski)
- fix potential OOB in usbhid_parse() (Terry Junge)
- make it possible to set hid_mouse_ignore_list dynamically (the same
way we handle other quirks) (Aditya Garg)
- other small assorted fixes and device ID additions
* tag 'hid-for-linus-2025060301' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
HID: multitouch: Disable touchpad on firmware level while not in use
HID: core: Add functions for HID drivers to react on first open and last close call
HID: HID_APPLETB_BL should depend on X86
HID: HID_APPLETB_KBD should depend on X86
HID: appletb-kbd: Use secs_to_jiffies() instead of msecs_to_jiffies()
HID: intel-thc-hid: intel-thc: make read-only arrays static const
HID: magicmouse: Apple Magic Mouse 2 USB-C support
HID: mcp2221: use new line value setter callbacks
HID: mcp2200: use new line value setter callbacks
HID: cp2112: use new line value setter callbacks
HID: cp2112: use lock guards
HID: cp2112: hold the lock for the entire direction_output() call
HID: cp2112: destroy mutex on driver detach
HID: intel-thc-hid: intel-quicki2c: pass correct arguments to acpi_evaluate_object
HID: corsair-void: Use to_delayed_work()
HID: hid-logitech: use sysfs_emit_at() instead of scnprintf()
HID: quirks: Add HID_QUIRK_IGNORE_MOUSE quirk
HID: usbhid: Eliminate recurrent out-of-bounds bug in usbhid_parse()
HID: Kysona: Add periodic online check
Use secs_to_jiffies() instead of msecs_to_jiffies() and avoid scaling
the module params 'appletb_tb_idle_timeout' and 'appletb_tb_dim_timeout'
to milliseconds. secs_to_jiffies() expands to simpler code and reduces
the size of 'hid-appletb-kbd.ko'.
Reformat the code to silence multiple checkpatch warnings.
No functional changes intended.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Aditya Garg <gargaditya08@live.com>
Tested-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following warnings were flagged by the kernel test robot:
drivers/hid/hid-appletb-kbd.c:405 appletb_kbd_probe() warn: inconsistent indenting
drivers/hid/hid-appletb-kbd.c:406 appletb_kbd_probe() warn: passing zero to 'dev_err_probe'
This patch aims at fixing those warnings.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202502152006.fBBCdEr3-lkp@intel.com/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-input/6263a1a2-4d50-41db-aa54-cfcb3e0523a4@stanley.mountain/
Fixes: 93a0fc4894 ("HID: hid-appletb-kbd: add support for automatic brightness control while using the touchbar")
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit simplifies the logic in appletb_kbd_inp_event used for
switching between the media and function keys on pressing the fn key.
We now also prevent touching the kbd->saved_mode variable in case the esc
key only mode is chosen.
The following small fixes have also been done in this patch:
- A small comment style error has been fixed
- Fixed spelling in MODULE_DESCRIPTION
- I have added myself to MODULE_AUTHOR
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit addresses the sparse warning flagged by the kernel test robot.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202502091105.ZsLoBSIh-lkp@intel.com/
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
On Windows, if there is no input by the user for 60 sec, the Touch Bar dims
automatically, and after further 15 sec, it turns off. On receiving input,
the Touch Bar resets the timer and goes back to full brightness. This patch
implements the same functionality.
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This patch adds support for the switching between the Media and Function
keys on the touchbar by pressing the Fn key on Apple Internal Keyboard.
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
The Touch Bars found on x86 Macs support two USB configurations: one
where the device presents itself as a HID keyboard and can display
predefined sets of keys, and one where the operating system has full
control over what is displayed. This commit adds a driver for the
display functionality of the first configuration.
Note that currently only T2 Macs are supported.
This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.
Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
