[PATCH 3/5] HID: playstation: sanity check DualSense calibration data.

[Roderick Colenbrander <roderick@gaikai.com>]

Make sure calibration values are defined to prevent potential kernel
crashes. This fixes a hypothetical issue for virtual or clone devices
inspired by a similar fix for DS4.

Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
---
 drivers/hid/hid-playstation.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 783ce9fd396e..11bb6caf7412 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -944,6 +944,7 @@ ATTRIBUTE_GROUPS(ps_device);
 
 static int dualsense_get_calibration_data(struct dualsense *ds)
 {
+	struct hid_device *hdev = ds->base.hdev;
 	short gyro_pitch_bias, gyro_pitch_plus, gyro_pitch_minus;
 	short gyro_yaw_bias, gyro_yaw_plus, gyro_yaw_minus;
 	short gyro_roll_bias, gyro_roll_plus, gyro_roll_minus;
@@ -954,6 +955,7 @@ static int dualsense_get_calibration_data(struct dualsense *ds)
 	int speed_2x;
 	int range_2g;
 	int ret = 0;
+	int i;
 	uint8_t *buf;
 
 	buf = kzalloc(DS_FEATURE_REPORT_CALIBRATION_SIZE, GFP_KERNEL);
@@ -1005,6 +1007,21 @@ static int dualsense_get_calibration_data(struct dualsense *ds)
 	ds->gyro_calib_data[2].sens_numer = speed_2x*DS_GYRO_RES_PER_DEG_S;
 	ds->gyro_calib_data[2].sens_denom = gyro_roll_plus - gyro_roll_minus;
 
+	/*
+	 * Sanity check gyro calibration data. This is needed to prevent crashes
+	 * during report handling of virtual, clone or broken devices not implementing
+	 * calibration data properly.
+	 */
+	for (i = 0; i < ARRAY_SIZE(ds->gyro_calib_data); i++) {
+		if (ds->gyro_calib_data[i].sens_denom == 0) {
+			hid_warn(hdev, "Invalid gyro calibration data for axis (%d), disabling calibration.",
+					ds->gyro_calib_data[i].abs_code);
+			ds->gyro_calib_data[i].bias = 0;
+			ds->gyro_calib_data[i].sens_numer = DS_GYRO_RANGE;
+			ds->gyro_calib_data[i].sens_denom = S16_MAX;
+		}
+	}
+
 	/*
 	 * Set accelerometer calibration and normalization parameters.
 	 * Data values will be normalized to 1/DS_ACC_RES_PER_G g.
@@ -1027,6 +1044,21 @@ static int dualsense_get_calibration_data(struct dualsense *ds)
 	ds->accel_calib_data[2].sens_numer = 2*DS_ACC_RES_PER_G;
 	ds->accel_calib_data[2].sens_denom = range_2g;
 
+	/*
+	 * Sanity check accelerometer calibration data. This is needed to prevent crashes
+	 * during report handling of virtual, clone or broken devices not implementing calibration
+	 * data properly.
+	 */
+	for (i = 0; i < ARRAY_SIZE(ds->accel_calib_data); i++) {
+		if (ds->accel_calib_data[i].sens_denom == 0) {
+			hid_warn(hdev, "Invalid accelerometer calibration data for axis (%d), disabling calibration.",
+					ds->accel_calib_data[i].abs_code);
+			ds->accel_calib_data[i].bias = 0;
+			ds->accel_calib_data[i].sens_numer = DS_ACC_RANGE;
+			ds->accel_calib_data[i].sens_denom = S16_MAX;
+		}
+	}
+
 err_free:
 	kfree(buf);
 	return ret;
-- 
2.38.1