From 336ecce920c9ed8aed5ec29ccfc6b4004bf8291a Mon Sep 17 00:00:00 2001 From: Kinsey Moore Date: Tue, 25 Mar 2014 15:52:55 +0000 Subject: [PATCH] chan_sip: Fix incorrect use of timers If update_provisional_keepalive() is called while send_provisional_keepalive_full() is waiting on the PVT lock, then pvt->provisional_keepalive_sched_id will be changed to a new sched_id value by update_provisional_keepalive(), but that new sched_id then may be overwritten with -1 by send_provisional_keepalive_full(), killing the pvt's reference to a schedule and "leaking" the reference. (closes issue ASTERISK-22079) Review: https://reviewboard.asterisk.org/r/3368/ Reported by: Jamuel Starkey, Matteo, Leif Madsen, Steve Davies Patches: provisional_keepalive_fix.diff uploaded by Steve Davies (license 5012) ........ Merged revisions 411088 from http://svn.asterisk.org/svn/asterisk/branches/1.8 git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@411089 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- channels/chan_sip.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/channels/chan_sip.c b/channels/chan_sip.c index 3eb3eae4dd..c6b196b662 100644 --- a/channels/chan_sip.c +++ b/channels/chan_sip.c @@ -4632,8 +4632,20 @@ static int send_provisional_keepalive_full(struct sip_pvt *pvt, int with_sdp) const char *msg = NULL; struct ast_channel *chan; int res = 0; + int old_sched_id = pvt->provisional_keepalive_sched_id; chan = sip_pvt_lock_full(pvt); + /* Check that nothing has changed while we were waiting for the lock */ + if (old_sched_id != pvt->provisional_keepalive_sched_id) { + /* Keepalive has been cancelled or rescheduled, clean up and leave */ + if (chan) { + ast_channel_unlock(chan); + chan = ast_channel_unref(chan); + } + sip_pvt_unlock(pvt); + dialog_unref(pvt, "dialog ref for provisional keepalive"); + return 0; + } if (!pvt->last_provisional || !strncasecmp(pvt->last_provisional, "100", 3)) { msg = "183 Session Progress"; @@ -4659,20 +4671,9 @@ static int send_provisional_keepalive_full(struct sip_pvt *pvt, int with_sdp) sip_pvt_unlock(pvt); -#if 0 - /* - * XXX BUG TODO - * - * Without this code, it appears as if this function is leaking its - * reference to the sip_pvt. However, adding it introduces a crash. - * This points to some sort of reference count imbalance elsewhere, - * but I'm not sure where ... - */ if (!res) { dialog_unref(pvt, "dialog ref for provisional keepalive"); } -#endif - return res; }