From 47c6d3ecdfc3fc354cf996f873a9f854c2325160 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Sun, 18 Dec 2011 17:05:04 +0100 Subject: qapi: protect against NULL QObject in qmp_input_get_object A NULL qobj can occur when a parameter is fetched via qdict_get, but the parameter is not in the command. By returning NULL, the caller can choose whether to raise a missing parameter error, an invalid parameter type error, or use a default value. For example, qom-set could can use this to reset a property to its default value, though at this time it will fail with "Invalid parameter type". In any case, anything is better than crashing! Reviewed-by: Anthony Liguori Signed-off-by: Paolo Bonzini Signed-off-by: Anthony Liguori --- qapi/qmp-input-visitor.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'qapi') diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index 8cbc0abcfd..c78022bb87 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -49,10 +49,12 @@ static const QObject *qmp_input_get_object(QmpInputVisitor *qiv, qobj = qiv->stack[qiv->nb_stack - 1].obj; } - if (name && qobject_type(qobj) == QTYPE_QDICT) { - return qdict_get(qobject_to_qdict(qobj), name); - } else if (qiv->nb_stack > 0 && qobject_type(qobj) == QTYPE_QLIST) { - return qlist_entry_obj(qiv->stack[qiv->nb_stack - 1].entry); + if (qobj) { + if (name && qobject_type(qobj) == QTYPE_QDICT) { + return qdict_get(qobject_to_qdict(qobj), name); + } else if (qiv->nb_stack > 0 && qobject_type(qobj) == QTYPE_QLIST) { + return qlist_entry_obj(qiv->stack[qiv->nb_stack - 1].entry); + } } return qobj; -- cgit v1.2.3