From ef8daaf696584f7c1d3e9f192de18b5b9f923bdc Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Mon, 23 Mar 2015 11:38:15 +1000 Subject: [PATCH] eventcomm: prevent possibly division by zero This came up as a kernel bug, but it's valid to create uinput devices with a min == max range for x/y. Technically valid, but effectively useless, so catch it, complain and hobble on along. Signed-off-by: Peter Hutterer Reviewed-by: Hans de Goede (cherry picked from commit 30866b97be6939b895327b930154ef758eed7ff8) --- src/eventcomm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/eventcomm.c b/src/eventcomm.c index 9e81b86..a08a3b3 100644 --- a/src/eventcomm.c +++ b/src/eventcomm.c @@ -437,6 +437,11 @@ event_query_axis_ranges(InputInfoPtr pInfo) event_get_abs(proto_data->evdev, ABS_Y, &priv->miny, &priv->maxy, &priv->synpara.hyst_y, &priv->resy); + if (priv->minx == priv->maxx || priv->miny == priv->maxy) { + xf86IDrvMsg(pInfo, X_ERROR, "Kernel bug: min == max on ABS_X/Y\n"); + return; + } + priv->has_pressure = libevdev_has_event_code(proto_data->evdev, EV_ABS, ABS_PRESSURE); priv->has_width = libevdev_has_event_code(proto_data->evdev, EV_ABS, ABS_TOOL_WIDTH); @@ -459,6 +464,11 @@ event_query_axis_ranges(InputInfoPtr pInfo) event_get_abs(proto_data->evdev, ABS_MT_POSITION_Y, &priv->miny, &priv->maxy, &priv->synpara.hyst_y, &priv->resy); + if (priv->minx == priv->maxx || priv->miny == priv->maxy) { + xf86IDrvMsg(pInfo, X_ERROR, "Kernel bug: min == max on ABS_MT_POSITION_X/Y\n"); + return; + } + proto_data->st_to_mt_offset[0] = priv->minx - st_minx; proto_data->st_to_mt_scale[0] = (priv->maxx - priv->minx) / (st_maxx - st_minx);