Bluetooth: btnxpuart: Fix out-of-bounds firmware read in nxp_recv_fw_req_v3()

Bluetooth: btnxpuart: Fix out-of-bounds firmware read in nxp_recv_fw_req_v3()

During the v3 firmware download the controller sends a v3_data_req with a
32 bit offset and a 16 bit len. nxp_recv_fw_req_v3() checks only the lower
bound of the offset and then sends firmware from that offset.

  nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction;
  serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
                          nxpdev->fw_dnld_v3_offset, len);

Nothing checks that fw_dnld_v3_offset + len stays within nxpdev->fw->size,
so a controller that asks for an offset or length past the firmware image
makes the driver read past the end of nxpdev->fw->data and send that
memory back over UART.

nxp_recv_fw_req_v1() already bounds the same write. Add the equivalent
check to the v3 path, reject the request when it falls outside the firmware
image, and zero len on the error path so the fw_v3_prev_sent bookkeeping at
free_skb stays consistent.

Fixes: 689ca16e5232 ("Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets")
Suggested-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Reviewed-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>