tree e51b552fc97a866e2664416635442f3a3000ec25
parent 58a7981be35289750a61cab56deb6effae2db7ce
author Andreas Henriksson <andreas.henriksson@endian.se> 1399282589 +0200
committer Andreas Henriksson <andreas.henriksson@endian.se> 1399282589 +0200

lockdown: avoid crashing when getting system buid fails

When userpref_read_system_buid fails to retrieve the buid,
systembuid will be set to NULL. It was then unconditionally passed
to plist_new_string - which will crash with a NULL argument.

See https://bugs.debian.org/730756 for people reporting this
happening in the real world.

See https://github.com/libimobiledevice/libimobiledevice/commit/1331f6baa1799e41003aa812c0d1bf36193535ea
("lockdown: Make sure to set SystemBUID in generated pair records")
for the commit where this problem was introduced.