On Wed, Jul 15, 2026 at 04:22:41PM +0200, Hari Mishal wrote: > nslots is derived from the ABS_MT_SLOT maximum reported by the > virtio device. A device could report a bogus maximum (e.g. -1) > making nslots = 0, which input_mt_init_slots() does not reject; > it returns success without allocating any slot storage, silently > leaving the device registered as multitouch capable with no > backing state.
So let's disable multitouch instead? > Reject non-positive slot counts before calling > input_mt_init_slots(). > > Assisted-by: gkh_clanker:t1000 > Signed-off-by: Hari Mishal <[email protected]> > --- > drivers/virtio/virtio_input.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c > index deec24e8e682..2cc19782cdd3 100644 > --- a/drivers/virtio/virtio_input.c > +++ b/drivers/virtio/virtio_input.c > @@ -312,6 +312,10 @@ static int virtinput_probe(struct virtio_device *vdev) > > if (test_bit(ABS_MT_SLOT, vi->idev->absbit)) { > nslots = input_abs_get_max(vi->idev, ABS_MT_SLOT) + 1; > + if (nslots <= 0) { > + err = -EINVAL; > + goto err_mt_init_slots; > + } > err = input_mt_init_slots(vi->idev, nslots, 0); > if (err) > goto err_mt_init_slots; > -- > 2.43.0
