From ebf55f4b31f14e7118ee3d59dd43fd9dc00d128d Mon Sep 17 00:00:00 2001
From: Neels Hofmeyr <neels@hofmeyr.de>
Date: Mon, 9 Mar 2020 21:01:56 +0100
Subject: [PATCH] fix segfault: unsolicited Paging Response

Do not crash when a Paging Response could not be associated with a VLR
subscriber.

Related: OS#4449
Change-Id: Ie117949dd6da86afaa1a0a6ac57bf2111f6cff43
---
 src/libmsc/paging.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/libmsc/paging.c b/src/libmsc/paging.c
index 743ce5c86..b288414d8 100644
--- a/src/libmsc/paging.c
+++ b/src/libmsc/paging.c
@@ -137,6 +137,11 @@ static void paging_concludes(struct vlr_subscr *vsub, struct msc_a *msc_a)
 	struct paging_request *pr, *pr_next;
 	struct paging_signal_data sig_data;
 
+	if (!vsub) {
+		/* A Paging Response has no subscriber. (Related: OS#4449) */
+		return;
+	}
+
 	osmo_timer_del(&vsub->cs.paging_response_timer);
 
 	llist_for_each_entry_safe(pr, pr_next, &vsub->cs.requests, entry) {