From fc0c128531ed55f058bfbad4f1348ebd9a0187f2 Mon Sep 17 00:00:00 2001 From: Maksim Davydov Date: Thu, 25 Aug 2022 19:52:47 +0300 Subject: [PATCH] chardev: fix segfault in finalize MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If finalize chardev-msmouse or chardev-wctable is called immediately after init it cases QEMU to crash with segfault. This happens because of QTAILQ_REMOVE in qemu_input_handler_unregister tries to dereference NULL pointer. For instance, this error can be reproduced via `qom-list-properties` command. Signed-off-by: Maksim Davydov Reviewed-by: Marc-André Lureau Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20220825165247.33704-1-davydov-max@yandex-team.ru> --- chardev/msmouse.c | 4 +++- chardev/wctablet.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/chardev/msmouse.c b/chardev/msmouse.c index 9006703023..ab8fe981d6 100644 --- a/chardev/msmouse.c +++ b/chardev/msmouse.c @@ -247,7 +247,9 @@ static void char_msmouse_finalize(Object *obj) { MouseChardev *mouse = MOUSE_CHARDEV(obj); - qemu_input_handler_unregister(mouse->hs); + if (mouse->hs) { + qemu_input_handler_unregister(mouse->hs); + } fifo8_destroy(&mouse->outbuf); } diff --git a/chardev/wctablet.c b/chardev/wctablet.c index e8b292c43c..43bdf6b608 100644 --- a/chardev/wctablet.c +++ b/chardev/wctablet.c @@ -319,7 +319,9 @@ static void wctablet_chr_finalize(Object *obj) { TabletChardev *tablet = WCTABLET_CHARDEV(obj); - qemu_input_handler_unregister(tablet->hs); + if (tablet->hs) { + qemu_input_handler_unregister(tablet->hs); + } } static void wctablet_chr_open(Chardev *chr,