From 5e763029dc207c99796adc1c3ace71cf6de59446 Mon Sep 17 00:00:00 2001
From: Daniel-Constantin Mierla <miconda@gmail.com>
Date: Thu, 25 Oct 2018 07:06:21 +0200
Subject: [PATCH] kex: safety check for accessing CSeq in per method stats

- GH #1687
---
 src/modules/kex/core_stats.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/modules/kex/core_stats.c b/src/modules/kex/core_stats.c
index 2f51a1f9555..ef4d85dad83 100644
--- a/src/modules/kex/core_stats.c
+++ b/src/modules/kex/core_stats.c
@@ -234,8 +234,17 @@ static int km_cb_req_stats(struct sip_msg *msg,
 static int km_cb_rpl_stats_by_method(struct sip_msg *msg,
 		unsigned int flags, void *param)
 {
-      int method = get_cseq(msg)->method_id;
-      int group = msg->first_line.u.reply.statuscode / 100 - 1;
+	int method = 0;
+	int group = 0;
+
+	if(msg==NULL) {
+		return -1;
+	}
+	if (!msg->cseq && (parse_headers(msg, HDR_CSEQ_F, 0) < 0 || !msg->cseq)) {
+		return -1;
+	}
+	method = get_cseq(msg)->method_id;
+	group = msg->first_line.u.reply.statuscode / 100 - 1;
 
       if (group >= 0 && group <= 5) {
             switch(method) {