| Message ID | 20230125-hid-unregister-leds-v2-3-689cc62fc878@diag.uniroma1.it |
|---|---|
| State | New |
| Headers | show |
| Series | HID: manually unregister leds on device removal to prevent UAFs | expand |
On Jan 31 2023, Pietro Borrello wrote: > Unregister the LED controllers before device removal, to prevent > unnecessary runs of dualsense_player_led_set_brightness(). > > Fixes: 8c0ab553b072 ("HID: playstation: expose DualSense player LEDs through LED class.") > Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> > > --- > > Contrary to the other patches in this series, failing to unregister > the led controller does not results into a use-after-free thanks > to the output_worker_initialized variable and the spinlock checks. And so we don't need that patch (nor for hid-sony.c) because we have a guard against scheduling a worker job when the device is being removed. So please drop 3,4,5 from this series, they are just making the code worse. Cheers, Benjamin > > Changes in v2: > - Unregister multicolor led controller > - Clarify UAF > - Link to v1: https://lore.kernel.org/all/20230125-hid-unregister-leds-v1-3-9a5192dcef16@diag.uniroma1.it/ > --- > drivers/hid/hid-playstation.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c > index 27c40894acab..f23186ca2d76 100644 > --- a/drivers/hid/hid-playstation.c > +++ b/drivers/hid/hid-playstation.c > @@ -1503,11 +1503,17 @@ static void dualsense_remove(struct ps_device *ps_dev) > { > struct dualsense *ds = container_of(ps_dev, struct dualsense, base); > unsigned long flags; > + int i; > > spin_lock_irqsave(&ds->base.lock, flags); > ds->output_worker_initialized = false; > spin_unlock_irqrestore(&ds->base.lock, flags); > > + for (i = 0; i < ARRAY_SIZE(ds->player_leds); i++) > + devm_led_classdev_unregister(&ps_dev->hdev->dev, &ds->player_leds[i]); > + > + devm_led_classdev_multicolor_unregister(&ps_dev->hdev->dev, &ds->lightbar); > + > cancel_work_sync(&ds->output_worker); > } > > > -- > 2.25.1
On Thu, 9 Feb 2023 at 09:59, Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > On Jan 31 2023, Pietro Borrello wrote: > > Unregister the LED controllers before device removal, to prevent > > unnecessary runs of dualsense_player_led_set_brightness(). > > > > Fixes: 8c0ab553b072 ("HID: playstation: expose DualSense player LEDs through LED class.") > > Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> > > > > --- > > > > Contrary to the other patches in this series, failing to unregister > > the led controller does not results into a use-after-free thanks > > to the output_worker_initialized variable and the spinlock checks. > > And so we don't need that patch (nor for hid-sony.c) because we have a > guard against scheduling a worker job when the device is being removed. > > So please drop 3,4,5 from this series, they are just making the code > worse. Sure. I kept them only due to the Roderick Colenbrander's comment, but I'm happy to remove them. For reference: > [...] I don't mind the change as it > prevents the work scheduling functions to get called unnecessarily. Link: https://lore.kernel.org/lkml/CAEc3jaCEKfqEJSV4=6GRj1Ry97xH+HwVSeEOZReNwkt=rLNvNQ@mail.gmail.com/ Thanks, Pietro
diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c index 27c40894acab..f23186ca2d76 100644 --- a/drivers/hid/hid-playstation.c +++ b/drivers/hid/hid-playstation.c @@ -1503,11 +1503,17 @@ static void dualsense_remove(struct ps_device *ps_dev) { struct dualsense *ds = container_of(ps_dev, struct dualsense, base); unsigned long flags; + int i; spin_lock_irqsave(&ds->base.lock, flags); ds->output_worker_initialized = false; spin_unlock_irqrestore(&ds->base.lock, flags); + for (i = 0; i < ARRAY_SIZE(ds->player_leds); i++) + devm_led_classdev_unregister(&ps_dev->hdev->dev, &ds->player_leds[i]); + + devm_led_classdev_multicolor_unregister(&ps_dev->hdev->dev, &ds->lightbar); + cancel_work_sync(&ds->output_worker); }
Unregister the LED controllers before device removal, to prevent unnecessary runs of dualsense_player_led_set_brightness(). Fixes: 8c0ab553b072 ("HID: playstation: expose DualSense player LEDs through LED class.") Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> --- Contrary to the other patches in this series, failing to unregister the led controller does not results into a use-after-free thanks to the output_worker_initialized variable and the spinlock checks. Changes in v2: - Unregister multicolor led controller - Clarify UAF - Link to v1: https://lore.kernel.org/all/20230125-hid-unregister-leds-v1-3-9a5192dcef16@diag.uniroma1.it/ --- drivers/hid/hid-playstation.c | 6 ++++++ 1 file changed, 6 insertions(+)