From 389e3a4459e3b61eea3a21aba560122dbca264e6 Mon Sep 17 00:00:00 2001 From: Ulrich Sibiller Date: Thu, 21 Jun 2018 22:08:08 +0200 Subject: ProcGetPointerMapping uses rep.nElts before it is initialized Backport of this xorg upstream commit (with omitting the mentioned d792ac125a0462a04a930af543cbc732f8cdab7d). commit 34cf559bcf99dad550527b5ff53f247f0e8e73ee Author: Keith Packard Date: Tue Jul 10 15:58:48 2012 -0700 ProcGetPointerMapping uses rep.nElts before it is initialized In: commit d792ac125a0462a04a930af543cbc732f8cdab7d Author: Alan Coopersmith Date: Mon Jul 9 19:12:43 2012 -0700 Use C99 designated initializers in dix Replies the initializer for the .length element of the xGetPointerMappingReply structure uses the value of rep.nElts, but that won't be set until after this initializer runs, so we get garbage in the length element and clients using it will generally wedge. Easy to verify: $ xmodmap -pp Fixed by creating a local nElts variable and using that. Signed-off-by: Keith Packard Reviewed-by: Alan Coopersmith Backported-to-NX-by: Ulrich Sibiller --- nx-X11/programs/Xserver/dix/devices.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'nx-X11/programs/Xserver') diff --git a/nx-X11/programs/Xserver/dix/devices.c b/nx-X11/programs/Xserver/dix/devices.c index d31ff8224..51cf3fef9 100644 --- a/nx-X11/programs/Xserver/dix/devices.c +++ b/nx-X11/programs/Xserver/dix/devices.c @@ -1156,17 +1156,20 @@ ProcGetKeyboardMapping(ClientPtr client) int ProcGetPointerMapping(ClientPtr client) { + int nElts; xGetPointerMappingReply rep = {0}; ButtonClassPtr butc = inputInfo.pointer->button; + nElts = (butc) ? butc->numButtons : 0; REQUEST_SIZE_MATCH(xReq); rep.type = X_Reply; + rep.nElts = nElts; rep.sequenceNumber = client->sequence; - rep.nElts = butc->numButtons; - rep.length = ((unsigned)rep.nElts + (4-1))/4; + rep.length = ((unsigned)nElts + (4-1))/4; WriteReplyToClient(client, sizeof(xGetPointerMappingReply), &rep); - WriteToClient(client, (int)rep.nElts, &butc->map[1]); + if (butc) + WriteToClient(client, nElts, &butc->map[1]); return Success; } -- cgit v1.2.3