From: Marcel Apfelbaum <marcel.a@redhat.com>
Date: Mon, 26 May 2014 12:40:55 +0000 (+0300)
Subject: qapi: Avoid output visitor crashing if it encounters a NULL value
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1d10b44546e2605b6dd8a006dcc0d03166649e2d;p=qemu.git

qapi: Avoid output visitor crashing if it encounters a NULL value

A NULL value is not added to visitor's stack, but there
is no check for that when the visitor tries to return
that value, leading to QEMU crash.

Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
---

diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c
index 74a5684ed3..96b338463e 100644
--- a/qapi/qmp-output-visitor.c
+++ b/qapi/qmp-output-visitor.c
@@ -66,6 +66,12 @@ static QObject *qmp_output_pop(QmpOutputVisitor *qov)
 static QObject *qmp_output_first(QmpOutputVisitor *qov)
 {
     QStackEntry *e = QTAILQ_LAST(&qov->stack, QStack);
+
+    /* FIXME - find a better way to deal with NULL values */
+    if (!e) {
+        return NULL;
+    }
+
     return e->value;
 }