[PATCH for-5.0 2/3] qmp: fix leak on callbacks that return both value and error

[Marc-André Lureau]

Direct leak of 4120 byte(s) in 1 object(s) allocated from:
    #0 0x7fa114931887 in __interceptor_calloc (/lib64/libasan.so.6+0xb0887)
    #1 0x7fa1144ad8f0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x588f0)
    #2 0x561e3c9c8897 in qmp_object_add 
/home/elmarco/src/qemu/qom/qom-qmp-cmds.c:291
    #3 0x561e3cf48736 in qmp_dispatch 
/home/elmarco/src/qemu/qapi/qmp-dispatch.c:155
    #4 0x561e3c8efb36 in monitor_qmp_dispatch 
/home/elmarco/src/qemu/monitor/qmp.c:145
    #5 0x561e3c8f09ed in monitor_qmp_bh_dispatcher 
/home/elmarco/src/qemu/monitor/qmp.c:234
    #6 0x561e3d08c993 in aio_bh_call /home/elmarco/src/qemu/util/async.c:136
    #7 0x561e3d08d0a5 in aio_bh_poll /home/elmarco/src/qemu/util/async.c:164
    #8 0x561e3d0a535a in aio_dispatch 
/home/elmarco/src/qemu/util/aio-posix.c:380
    #9 0x561e3d08e3ca in aio_ctx_dispatch 
/home/elmarco/src/qemu/util/async.c:298
    #10 0x7fa1144a776e in g_main_context_dispatch 
(/lib64/libglib-2.0.so.0+0x5276e)

Signed-off-by: Marc-André Lureau <address@hidden>
---
 qapi/qmp-dispatch.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index c30c7ff9e1..79347e0864 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -155,6 +155,8 @@ QDict *qmp_dispatch(const QmpCommandList *cmds, QObject 
*request,
     cmd->fn(args, &ret, &err);
     qobject_unref(args);
     if (err) {
+        /* or assert(!ret) after reviewing all handlers: */
+        qobject_unref(ret);
         goto out;
     }
 
-- 
2.26.0.rc2.42.g98cedd0233