Merged revisions 325339 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r325339 | dvossel | 2011-06-28 15:31:00 -0500 (Tue, 28 Jun 2011) | 4 lines

  Fixes locking inversion caused by holding sip pvt lock during async_goto.

  (closes ASTERISK-17352)
........

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@325345 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index f3a9693165bea060b075b60a1f9e3800505abc9f..a4adb6f3656c01b809eed86a088d27b60f61db44 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -23441,13 +23441,21 @@ static int handle_request_refer(struct sip_pvt *p, struct sip_request *req, int
        }
        ast_set_flag(&p->flags[0], SIP_DEFER_BYE_ON_TRANSFER);  /* Delay hangup */
 
-
-       /* For blind transfers, move the call to the new extensions. For attended transfers on multiple
-          servers - generate an INVITE with Replaces. Either way, let the dial plan decided  */
-       /* indicate before masquerade so the indication actually makes it to the real channel
-          when using local channels with MOH passthru */
-       ast_indicate(current.chan2, AST_CONTROL_UNHOLD);
-       res = ast_async_goto(current.chan2, p->refer->refer_to_context, p->refer->refer_to, 1);
+       {
+               char *refer_to_context = ast_strdupa(p->refer->refer_to_context);
+               char *refer_to = ast_strdupa(p->refer->refer_to);
+
+               /* Do not hold the pvt lock during the indicate and async_goto. Those functions
+                * lock channels which will invalidate locking order if the pvt lock is held.*/
+               ao2_unlock(p);
+               /* For blind transfers, move the call to the new extensions. For attended transfers on multiple
+                * servers - generate an INVITE with Replaces. Either way, let the dial plan decided  */
+               /* indicate before masquerade so the indication actually makes it to the real channel
+                *when using local channels with MOH passthru */
+               ast_indicate(current.chan2, AST_CONTROL_UNHOLD);
+               res = ast_async_goto(current.chan2, refer_to_context, refer_to, 1);
+               ao2_lock(p);
+       }
 
        if (!res) {
                ast_manager_event_multichan(EVENT_FLAG_CALL, "Transfer", 2, chans,