Some people had difficulties to get access to modified sources in the recent past, or the GPL license contract has not been delivered, or a device didn't come with a statement that is carries OS-firmware, or source code was denied access after requesting it.
No matter if you deal with hardware carrying OS-firmware, or simply downloaded OS-Software:
According to the GPL V3 the sources need to be available, you need to be informed about the fact that OS-Software is involved and you should have got the GPLV3 - license in full text format.
If you experience any of such issues, please post them here. They will be taken care of.
Further information can be found here: