From d173e93aa76cd8c484f0d1eef7d0110fb4e37202 Mon Sep 17 00:00:00 2001
From: mbellomi <massimiliano@scientiamobile.com>
Date: Tue, 21 May 2019 15:32:48 +0200
Subject: [PATCH] BUG/MEDIUM: WURFL: segfault in wurfl-get() with missing info.

A segfault may happen in ha_wurfl_get() when dereferencing information not
present in wurfl-information-list. Check the node retrieved from the tree,
not its container.

This fix must be backported to 1.9.
---
 src/wurfl.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/wurfl.c b/src/wurfl.c
index 325cba649..7167a929f 100644
--- a/src/wurfl.c
+++ b/src/wurfl.c
@@ -514,9 +514,10 @@ static int ha_wurfl_get(const struct arg *args, struct sample *smp, const char *
 	while (args[i].data.str.area) {
 		chunk_appendf(temp, "%c", global_wurfl.information_list_separator);
 		node = ebst_lookup(&global_wurfl.btree, args[i].data.str.area);
-		wn = container_of(node, wurfl_data_t, nd);
 
-		if (wn) {
+		if (node) {
+
+			wn = container_of(node, wurfl_data_t, nd);
 
 			switch(wn->type) {
 			case HA_WURFL_DATA_TYPE_UNKNOWN :