[OpenSIPS-Devel] [OpenSIPS/opensips] 71050f: dialog: fix deadlock when freeing a cell on timer

[Razvan Crainea]

  Branch: refs/heads/2.3
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 71050fd9623b492c12fab5f1d8aa02c58559067c
      https://github.com/OpenSIPS/opensips/commit/71050fd9623b492c12fab5f1d8aa02c58559067c
  Author: Razvan Crainea <razvan at opensips.org>
  Date:   2018-09-14 (Fri, 14 Sep 2018)

  Changed paths:
    M modules/dialog/dlg_db_handler.c

  Log Message:
  -----------
  dialog: fix deadlock when freeing a cell on timer

When freeing a dialog on timer, sequential destroy callbacks might try
to fetch the dialog lock, resulting in a deadlock. The spotted backtrace
is dialog_update_db -> destroy_dlg -> free_dlg_dlg ->
destroy_dlg_callbacks_list -> unref_acc_ctx -> free_acc_ctx ->
store_dlg_value

Thanks go to Jonathan Hulme for spotting this and offering testing

(cherry picked from commit 6fcbcc816b6d8224ed97f14cec74181c0fe6423f)



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