From 200a210323f477d60e280d15e09ca39bedd81a7c Mon Sep 17 00:00:00 2001 From: Marc Mutz Date: Tue, 4 Jan 2022 19:43:49 +0100 Subject: QWindow: fix UB (invalid static_cast) Do the cast to QMouseEvent only after we determined that it's actually a QMouseEvent. Says ubsan: src/gui/kernel/qwindow.cpp:2558:27: runtime error: downcast of address 0x7fffca0e5af0 which does not point to an object of type 'QMouseEvent' 0x7fffca0e5af0: note: object is of type 'QShowEvent' ff 7f 00 00 b0 09 01 b8 61 7f 00 00 11 00 00 00 00 00 00 00 b3 8a b5 41 00 00 00 00 80 50 5a cc ^~~~~~~~~~~~~~~~~~~~~~~ vptr for 'QShowEvent' Only cast _after_ determining that `ev` is-a mouse event. Amends 3d71c4b740d23d5c3f380f495990f35ea17dc2a0. Change-Id: I8455c998e2f4390a1483c1a097eb095358963ace Reviewed-by: Volker Hilsheimer (cherry picked from commit efe4863f837834c1664e37bf439bdec399f1dc88) Reviewed-by: Qt Cherry-pick Bot --- src/gui/kernel/qwindow.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'src/gui/kernel') diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp index 030628b5db..a167d6e249 100644 --- a/src/gui/kernel/qwindow.cpp +++ b/src/gui/kernel/qwindow.cpp @@ -2556,7 +2556,12 @@ bool QWindow::event(QEvent *ev) static const QEvent::Type contextMenuTrigger = QGuiApplicationPrivate::platformTheme()->themeHint(QPlatformTheme::ContextMenuOnMouseRelease).toBool() ? QEvent::MouseButtonRelease : QEvent::MouseButtonPress; - if (QMouseEvent *me = static_cast(ev); + auto asMouseEvent = [](QEvent *ev) { + const auto t = ev->type(); + return t == QEvent::MouseButtonPress || t == QEvent::MouseButtonRelease + ? static_cast(ev) : nullptr ; + }; + if (QMouseEvent *me = asMouseEvent(ev); me && ev->type() == contextMenuTrigger && me->button() == Qt::RightButton) { QSinglePointEvent *pev = static_cast(ev); QContextMenuEvent e(QContextMenuEvent::Mouse, me->position().toPoint(), -- cgit v1.2.3