Re: [PATCH v2] HID: hid-input: clear unmapped usages

[Jiri Kosina]

On Fri, 13 Dec 2019, Benjamin Tissoires wrote:

> > > We should not be leaving half-mapped usages with potentially invalid
> > > keycodes, as that may confuse hidinput_find_key() when the key is located
> > > by index, which may end up feeding way too large keycode into the VT
> > > keyboard handler and cause OOB write there:
> > >
> > > BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
> > > BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> > > BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> > > Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
> > > ...
> > >  kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> > >  kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> > >  input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
> > >  input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
> > >  input_pass_values drivers/input/input.c:949 [inline]
> > >  input_set_keycode+0x290/0x320 drivers/input/input.c:954
> > >  evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
> > >  evdev_do_ioctl drivers/input/evdev.c:1150 [inline]
> > >
> > > Reported-by: syzbot+19340dff067c2d3835c0@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > > ---
> > >
> > > v2: fixed up interaction with hid-multitouch according to Benjamin's
> > > feedback
> > >
> > > Please consider tagging for stable.
> >
> > I'd like to push this for 5.5 (and tag for stable), but would prefer this
> > to have gone through the full battery of Benjamin's testing infrastructure
> > first.
> >
> > Benjamin, did you have chance to run Dmitry's patch through your
> > machinery?
> 
> yep, this one was OK, so:
> Tested-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

Thanks, I am queuing this in for-5.5/upstream-fixes.

-- 
Jiri Kosina
SUSE Labs