fdo-mirrors/libinput
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/libinput/libinput.git synced 2026-06-10 00:58:31 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

pad: ignore invalid strip axis values

Browse source 
we call log2() on both maximum and value so ensure they're never zero or
negative.

Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1486>
This commit is contained in:
Peter Hutterer 2026-06-03 14:33:14 +10:00 • committed by Marge Bot
parent 04a35384e6
commit af084f375c
2 changed files with 52 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
src/evdev-tablet-pad.c
View file

@ -237,6 +237,9 @@ normalize_wacom_ring(const struct input_absinfo *absinfo)
static inline double
normalize_wacom_strip(const struct input_absinfo *absinfo)
{
if (absinfo->maximum <= 1 || absinfo->value <= 0)
return 0.0;
/* strip axes don't use a proper value, they just shift the bit left
* for each position. 0 isn't a real value either, it's only sent on
* finger release */

49
test/test-pad.c
View file

@ -1113,6 +1113,54 @@ START_TEST(pad_keys)
}
END_TEST
START_TEST(pad_strip_wacom_degenerate_max)
{
struct libinput_event *ev;
struct libinput_event_tablet_pad *pev;
double pos;
/* Override ABS_RX to have maximum=1, which would cause
* log2(1) = 0 and division by zero in normalize_wacom_strip()
* without the guard. */
/* clang-format off */
struct input_absinfo abs_override[] = {
{ ABS_RX, 0, 1, 0, 0, 0 },
{ -1, -1, -1, -1, -1, -1 },
};
/* clang-format on */
_litest_context_destroy_ struct libinput *li = litest_create_context();
struct litest_device *dev =
litest_add_device_with_overrides(li,
LITEST_WACOM_INTUOS3_PAD,
NULL,
NULL,
abs_override,
NULL);
litest_drain_events(li);
/* Send strip events - value 1 with max 1 triggers
* log2(1)/log2(1) = 0/0 = NaN without the guard */
litest_pad_strip_start(dev, 100);
litest_dispatch(li);
ev = libinput_get_event(li);
pev = litest_is_pad_strip_event(ev, 0, LIBINPUT_TABLET_PAD_STRIP_SOURCE_FINGER);
pos = libinput_event_tablet_pad_get_strip_position(pev);
/* Without the fix, pos would be NaN from 0/0 division.
* With the fix, pos must be a valid finite number. */
litest_assert_double_ge(pos, 0.0);
litest_assert_double_le(pos, 1.0);
libinput_event_destroy(ev);
litest_pad_strip_end(dev);
litest_drain_events(li);
litest_device_destroy(dev);
}
END_TEST
START_TEST(pad_send_events_disabled)
{
struct litest_device *dev = litest_current_device();
@ -1171,6 +1219,7 @@ TEST_COLLECTION(pad)
litest_add(pad_has_strip, LITEST_STRIP, LITEST_ANY);
litest_add(pad_strip, LITEST_STRIP, LITEST_ANY);
litest_add(pad_strip_finger_up, LITEST_STRIP, LITEST_ANY);
litest_add_no_device(pad_strip_wacom_degenerate_max);
litest_add(pad_has_dial, LITEST_DIAL, LITEST_ANY);
litest_add(pad_dial_low_res, LITEST_DIAL, LITEST_ANY);