qmicli: assertion failed with --nas-get-serving-system and ZTE MF683

[Aleksander Morgado]

Hey Shawn,

Thanks for the additional logs.

The problem here is that the "Detailed Service Status" TLV (0x21) in the
"NAS Get Serving System" (0x0024) message is supposed to be a sequence
of 5 bytes, but your modem only sends 4 bytes. I do not know if that is
a bug in the firmware or a bug in the documentation.

Anyway, I developed some TLV validation logic which will check, before
reading the contents of the TLV, if the TLV has all the fields we
expect. This should at least avoid future crashes for issues similar to
the one you have. If a TLV is assumed invalid, we just skip that one,
not the whole message (unless it's a mandatory TLV).

The code is in the 'validate-tlv' branch in upstream git; could you give
it a try?

Cheers!

-- 
Aleksander