[PATCH 4.6 43/96] Input: synaptics-rmi4 - fix maximum size check for F12 control register 8

[Greg Kroah-Hartman]

4.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrew Duggan <aduggan@xxxxxxxxxxxxx>

commit e4add7b6beaff4061693d0632bc1dcb306edba10 upstream.

According to the RMI4 spec the maximum size of F12 control register 8 is
15 bytes. The current code incorrectly reports an error if control 8 is
greater then 14. Making sensors with a control register 8 with 15 bytes
unusable.

Signed-off-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
Reported-by: Chris Healy <cphealy@xxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/input/rmi4/rmi_f12.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/input/rmi4/rmi_f12.c
+++ b/drivers/input/rmi4/rmi_f12.c
@@ -66,7 +66,7 @@ static int rmi_f12_read_sensor_tuning(st
 	struct rmi_device *rmi_dev = fn->rmi_dev;
 	int ret;
 	int offset;
-	u8 buf[14];
+	u8 buf[15];
 	int pitch_x = 0;
 	int pitch_y = 0;
 	int clip_x_low = 0;
@@ -86,9 +86,10 @@ static int rmi_f12_read_sensor_tuning(st
 
 	offset = rmi_register_desc_calc_reg_offset(&f12->control_reg_desc, 8);
 
-	if (item->reg_size > 14) {
-		dev_err(&fn->dev, "F12 control8 should be 14 bytes, not: %ld\n",
-			item->reg_size);
+	if (item->reg_size > sizeof(buf)) {
+		dev_err(&fn->dev,
+			"F12 control8 should be no bigger than %zd bytes, not: %ld\n",
+			sizeof(buf), item->reg_size);
 		return -ENODEV;
 	}