From: Björn Esser <besser82@fedoraproject.org>
Date: Wed, 13 Dec 2017 18:22:52 +0000 (+0100)
Subject: json_object: Avoid invalid free (and thus a segfault) when ref_count gets < 0
X-Git-Tag: json-c-0.14-20200419~139^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F389%2Fhead;p=thirdparty%2Fjson-c.git

json_object: Avoid invalid free (and thus a segfault) when ref_count gets < 0
---

diff --git a/json_object.c b/json_object.c
index 042477a7..7c7438d8 100644
--- a/json_object.c
+++ b/json_object.c
@@ -182,6 +182,11 @@ int json_object_put(struct json_object *jso)
 {
 	if(!jso) return 0;
 
+	/* Avoid invalid free and crash explicitly instead of (silently)
+	 * segfaulting.
+	 */
+	assert(jso->_ref_count > 0);
+
 #if defined(HAVE_ATOMIC_BUILTINS) && defined(ENABLE_THREADING)
 	/* Note: this only allow the refcount to remain correct
 	 * when multiple threads are adjusting it.  It is still an error