[Qemu-devel] [PATCH] json-parser: Fix potential NULL pointer segfault

[Stefan Weil <sw@weilnetz.de>]

Report from smatch:
json-parser.c:474 parse_object(62) error: potential null derefence 'dict'.
json-parser.c:553 parse_array(75) error: potential null derefence 'list'.

Label 'out' in json-parser.c can be called with list == NULL
which is passed to QDECREF.

Modify QDECREF to handle a NULL argument (inline function qobject_decref
already handles them, too).

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---

I did not change QINCREF because there are currently no errors caused
by that rarely used macro.

This patch can be used instead of the previous patch which fixed
the problem directly in json-parser.c
(see http://patchwork.ozlabs.org/patch/181129/).

Regards,
Stefan Weil

 qobject.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qobject.h b/qobject.h
index d42386d..9124649 100644
--- a/qobject.h
+++ b/qobject.h
@@ -71,7 +71,7 @@ typedef struct QObject {
 
 /* High-level interface for qobject_decref() */
 #define QDECREF(obj)              \
-    qobject_decref(QOBJECT(obj))
+    qobject_decref(obj ? QOBJECT(obj) : NULL)
 
 /* Initialize an object to default values */
 #define QOBJECT_INIT(obj, qtype_type)   \
-- 
1.7.10