tree 54362e84e949e7b7c8e6d96e2e056dec015733c6
parent 49692af2d33d90c23fac3b051df27bcb43245163
author Neels Hofmeyr <nhofmeyr@sysmocom.de> 1482368283 +0100
committer Neels Hofmeyr <nhofmeyr@sysmocom.de> 1486078442 +0100

gsm0408_rcv_cc: guard against NULL subscriber

Check conn->subscr against NULL.

gsm0408_rcv_cc() dereferences many conn members without checking presence: the
bts and lchan members may be expected to be NULL in the ongoing MSC split and
3G developments.

But the conn->subscr is initially NULL, so an MS sending a CC message before
something like a LU or CM Service Request will result in a segfault. Prevent
that.

Note: the upcoming VLR will be more restrictive on what messages are processed,
this is a "backport" to the situation on current master.

Change-Id: If067db7cc0dd3210d9eb1da15be6b637795a3ecf