[OpenSIPS-Devel] [OpenSIPS/opensips] fc5859: registrar: Fix possible crash in remove_ip_port()

[Liviu Chircu]

  Branch: refs/heads/3.3
  Home:   https://github.com/OpenSIPS/opensips
  Commit: fc5859d8993b194f268bfb6e478700f74f5a4c09
      https://github.com/OpenSIPS/opensips/commit/fc5859d8993b194f268bfb6e478700f74f5a4c09
  Author: Liviu Chircu <liviu at opensips.org>
  Date:   2023-02-07 (Tue, 07 Feb 2023)

  Changed paths:
    M modules/registrar/save.c

  Log Message:
  -----------
  registrar: Fix possible crash in remove_ip_port()

The release_urecord() function may actually delete the AoR on the spot,
including the map_t node which the iterator is currently at!  This was
causing an invalid SHM memory read when calling iterator_next(),
potentially running into a crash.

The fix is to advance the iterator ahead of time, before the
release_urecord() call.

Fixes #2954

(cherry picked from commit a117dc8dc5d9eab24d2bc646fb70e6afbaaced94)