From b073244c511f9634de57ea401ab9dbebcf2390e8 Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Mon, 25 Jan 2016 16:51:25 -0600
Subject: [PATCH] res_pjsip_pubsub: Prevent crash from AMI command on freed
 subscription.

A test recently uncovered that running an ill-timed AMI command to show
inbound subscriptions could cause a crash since Asterisk will try to
operate on a freed subscription.

The fix for this is to remove the subscription tree from the list of
subscriptions at the time that we are sending our final NOTIFY request
out. This way, as the subscription is in the process of dying, it is
inaccessible from AMI.

Change-Id: Ic0239003d8d73e04c47c12dd2a7e23867e5b5b23
---
 res/res_pjsip_pubsub.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index a703e29a15..dc7f5ed9e6 100644
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -1202,8 +1202,6 @@ static void subscription_tree_destructor(void *obj)
 
 	ast_debug(3, "Destroying subscription tree %p\n", sub_tree);
 
-	remove_subscription(sub_tree);
-
 	ao2_cleanup(sub_tree->endpoint);
 
 	destroy_subscriptions(sub_tree->root);
@@ -3295,6 +3293,7 @@ static void pubsub_on_evsub_state(pjsip_evsub *evsub, pjsip_event *event)
 		}
 	}
 
+	remove_subscription(sub_tree);
 	pjsip_evsub_set_mod_data(evsub, pubsub_module.id, NULL);
 	sub_tree->evsub = NULL;
 	ast_sip_dialog_set_serializer(sub_tree->dlg, NULL);
-- 
GitLab