From 552de314bf0c8e4de5d002bdd1c12388c2f42283 Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Mon, 19 Dec 2011 14:52:41 +1000 Subject: dix: don't retrieve the syncEvents tail on an empty list An empty list points to itself but syncEvents has the list head only and is of a different format than the elements. Thus, casting it to a QdEventPtr gives us garbage. Segfaults with XTS test case Xlib13/XGrabKeyboard Introduced in 7af23259d88f4c28ed21140f82cc03b3724c06bb. Reported-by: Aaron Plattner Signed-off-by: Peter Hutterer Reviewed-by: Chase Douglas --- dix/events.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'dix') diff --git a/dix/events.c b/dix/events.c index 48cf7a244..d80290360 100644 --- a/dix/events.c +++ b/dix/events.c @@ -1116,13 +1116,14 @@ NoticeEventTime(InternalEvent *ev) void EnqueueEvent(InternalEvent *ev, DeviceIntPtr device) { - QdEventPtr tail; + QdEventPtr tail = NULL; QdEventPtr qe; SpritePtr pSprite = device->spriteInfo->sprite; int eventlen; DeviceEvent *event = &ev->device_event; - tail = list_last_entry(&syncEvents.pending, QdEventRec, next); + if (!list_is_empty(&syncEvents.pending)) + tail = list_last_entry(&syncEvents.pending, QdEventRec, next); NoticeTime((InternalEvent*)event); -- cgit v1.2.3