From: Russell Bryant <russell@russellbryant.com>
Date: Wed, 13 Oct 2010 15:29:21 +0000 (+0000)
Subject: Merged revisions 291392 via svnmerge from
X-Git-Tag: 1.6.2.15-rc1~44
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3442a369aa497c88813a3d8df1bc54b2b240af4c;p=thirdparty%2Fasterisk.git

Merged revisions 291392 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r291392 | russell | 2010-10-13 10:23:19 -0500 (Wed, 13 Oct 2010) | 6 lines

  Lock pvt so pvt->owner can't disappear when queueing up a frame.

  This fixes a crash due to a hangup race condition.

  ABE-2601
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@291393 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 26872d7e12..2e8cfe2309 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -4008,9 +4008,21 @@ static int __sip_autodestruct(const void *data)
 	/* Reset schedule ID */
 	p->autokillid = -1;
 
+
+	/*
+	 * Lock both the pvt and the channel safely so that we can queue up a frame.
+	 */
+	sip_pvt_lock(p);
+	while (p->owner && ast_channel_trylock(p->owner)) {
+		sip_pvt_unlock(p);
+		sched_yield();
+		sip_pvt_lock(p);
+	}
+
 	if (p->owner) {
 		ast_log(LOG_WARNING, "Autodestruct on dialog '%s' with owner in place (Method: %s)\n", p->callid, sip_methods[p->method].text);
 		ast_queue_hangup_with_cause(p->owner, AST_CAUSE_PROTOCOL_ERROR);
+		ast_channel_unlock(p->owner);
 	} else if (p->refer && !p->alreadygone) {
 		ast_debug(3, "Finally hanging up channel after transfer: %s\n", p->callid);
 		transmit_request_with_auth(p, SIP_BYE, 0, XMIT_RELIABLE, 1);
@@ -4024,7 +4036,11 @@ static int __sip_autodestruct(const void *data)
 		/* sip_destroy(p); */		/* Go ahead and destroy dialog. All attempts to recover is done */
 		/* sip_destroy also absorbs the reference */
 	}
+
+	sip_pvt_unlock(p);
+
 	dialog_unref(p, "The ref to a dialog passed to this sched callback is going out of scope; unref it.");
+
 	return 0;
 }