platform/chrome: sensorhub: Fix memory overread in ring handler

In the Linux kernel, the following vulnerability has been resolved: platform/chrome: sensorhub: Fix memory overread in ring handler `max_response` and `sensor_num` are read from different EC commands: - `max_response` is from cros_ec_get_proto_info(). ec_dev->max_response = info->max_response_packet_size - sizeof(struct ec_host_response); - `sensor_num` is from cros_ec_get_sensor_count(). sensor_num = cros_ec_get_sensor_count(ec); With a malfunctioning EC firmware, it is possible that the `msg->insize` (i.e., `fifo_info_length` in the context) could be clamped in cros_ec_cmd_xfer() because `msg->insize` is greater than `max_response`. int fifo_info_length = sizeof(struct ec_response_motion_sense_fifo_info) + sizeof(u16) * sensorhub->sensor_num; This means the number of read bytes could be less than expected. As a result, the subsequent memcpy() in cros_ec_sensorhub_ring_handler() overreads the `resp->fifo_info` buffer. Check the return value of cros_ec_cmd_xfer_status() and abort if the number of bytes read does not match the expected length.

Where it's fixed