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| author | Laszlo Ersek <lersek@redhat.com> | 2012-03-20 11:22:48 +0100 |
|---|---|---|
| committer | Luiz Capitulino <lcapitulino@redhat.com> | 2012-03-27 09:11:00 -0300 |
| commit | f24582d6ad8a080e008974c000bf0ae635d036ac (patch) | |
| tree | 8724e20f9af9e8c9e6c8e3e90b2e94fb30a51d98 /qapi | |
| parent | 8a22565b7c2d1920b02b94e7a8021c65895a3a22 (diff) | |
| download | qemu-f24582d6ad8a080e008974c000bf0ae635d036ac.zip qemu-f24582d6ad8a080e008974c000bf0ae635d036ac.tar.gz qemu-f24582d6ad8a080e008974c000bf0ae635d036ac.tar.bz2 | |
qapi: fix double free in qmp_output_visitor_cleanup()
Stack entries in QmpOutputVisitor are navigation links (weak references),
except the bottom (ie. least recently added) entry, which owns the root
QObject [1]. Make qmp_output_visitor_cleanup() drop the stack entries,
then release the QObject tree by the root.
Attempting to serialize an invalid enum inside a dictionary is an example
for triggering the double free.
[1] http://lists.nongnu.org/archive/html/qemu-devel/2012-03/msg03276.html
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/qmp-output-visitor.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c index e0697b0..2bce9d5 100644 --- a/qapi/qmp-output-visitor.c +++ b/qapi/qmp-output-visitor.c @@ -199,14 +199,16 @@ void qmp_output_visitor_cleanup(QmpOutputVisitor *v) { QStackEntry *e, *tmp; + /* The bottom QStackEntry, if any, owns the root QObject. See the + * qmp_output_push_obj() invocations in qmp_output_add_obj(). */ + QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v); + QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) { QTAILQ_REMOVE(&v->stack, e, node); - if (e->value) { - qobject_decref(e->value); - } g_free(e); } + qobject_decref(root); g_free(v); } |