From 2545d1b4d14f8290c048b7cd6b4351792f57344e Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 11 May 2023 12:08:37 -0700 Subject: [PATCH] Input: psmouse - fix OOB access in Elantech protocol commit 7b63a88bb62ba2ddf5fcd956be85fe46624628b9 upstream. The kernel only allocate 5 MT slots; check that transmitted slot ID falls within the acceptable range. Link: https://lore.kernel.org/r/ZFnEL91nrT789dbG@google.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/input/mouse/elantech.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index ece97f8c6a3e..2118b2075f43 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -674,10 +674,11 @@ static void process_packet_head_v4(struct psmouse *psmouse) struct input_dev *dev = psmouse->dev; struct elantech_data *etd = psmouse->private; unsigned char *packet = psmouse->packet; - int id = ((packet[3] & 0xe0) >> 5) - 1; + int id; int pres, traces; - if (id < 0) + id = ((packet[3] & 0xe0) >> 5) - 1; + if (id < 0 || id >= ETP_MAX_FINGERS) return; etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2]; @@ -707,7 +708,7 @@ static void process_packet_motion_v4(struct psmouse *psmouse) int id, sid; id = ((packet[0] & 0xe0) >> 5) - 1; - if (id < 0) + if (id < 0 || id >= ETP_MAX_FINGERS) return; sid = ((packet[3] & 0xe0) >> 5) - 1; @@ -728,7 +729,7 @@ static void process_packet_motion_v4(struct psmouse *psmouse) input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x); input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y); - if (sid >= 0) { + if (sid >= 0 && sid < ETP_MAX_FINGERS) { etd->mt[sid].x += delta_x2 * weight; etd->mt[sid].y -= delta_y2 * weight; input_mt_slot(dev, sid);