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authorEric Blake2015-11-06 07:35:27 +0100
committerMarkus Armbruster2015-11-09 16:45:05 +0100
commitcc9f60d4a2a4bf2578a9309a18f1c4602c9f5ce7 (patch)
treeec55f8cf81cc96079d17d2eeef3c759e51c28bc6
parentqapi: Strengthen test of TestStructList (diff)
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qobject: Protect against use-after-free in qobject_decref()
Adding an assertion to qobject_decref() will ensure that a programming error causing use-after-free will result in immediate failure (provided no other thread has started using the memory) instead of silently attempting to wrap refcnt around and leaving the problem to potentially bite later at a harder point to diagnose. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1446791754-23823-4-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
-rw-r--r--include/qapi/qmp/qobject.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index c856f553b7..4b96ed5837 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -90,6 +90,7 @@ static inline void qobject_incref(QObject *obj)
*/
static inline void qobject_decref(QObject *obj)
{
+ assert(!obj || obj->refcnt);
if (obj && --obj->refcnt == 0) {
assert(obj->type != NULL);
assert(obj->type->destroy != NULL);