1 files changed, 71 insertions, 0 deletions
diff --git a/package/x11r7/xserver_xorg-server/1.14.7/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch b/package/x11r7/xserver_xorg-server/1.14.7/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch
new file mode 100644
index 0000000000..12da5f5cba
--- /dev/null
+++ b/package/x11r7/xserver_xorg-server/1.14.7/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch
@@ -0,0 +1,71 @@
+From 215f894965df5fb0bb45b107d84524e700d2073c Mon Sep 17 00:00:00 2001
+From: Michal Srb <msrb@suse.com>
+Date: Wed, 24 May 2017 15:54:40 +0300
+Subject: [PATCH] dix: Disallow GenericEvent in SendEvent request.
+
+The SendEvent request holds xEvent which is exactly 32 bytes long, no more,
+no less. Both ProcSendEvent and SProcSendEvent verify that the received data
+exactly match the request size. However nothing stops the client from passing
+in event with xEvent::type = GenericEvent and any value of
+xGenericEvent::length.
+
+In the case of ProcSendEvent, the event will be eventually passed to
+WriteEventsToClient which will see that it is Generic event and copy the
+arbitrary length from the receive buffer (and possibly past it) and send it to
+the other client. This allows clients to copy unitialized heap memory out of X
+server or to crash it.
+
+In case of SProcSendEvent, it will attempt to swap the incoming event by
+calling a swapping function from the EventSwapVector array. The swapped event
+is written to target buffer, which in this case is local xEvent variable. The
+xEvent variable is 32 bytes long, but the swapping functions for GenericEvents
+expect that the target buffer has size matching the size of the source
+GenericEvent. This allows clients to cause stack buffer overflows.
+
+Signed-off-by: Michal Srb <msrb@suse.com>
+Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
+Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ dix/events.c  | 6 ++++++
+ dix/swapreq.c | 7 +++++++
+ 2 files changed, 13 insertions(+)
+
+diff --git a/dix/events.c b/dix/events.c
+index 3e3a01ef9..d3a33ea3f 100644
+--- a/dix/events.c
++++ b/dix/events.c
+@@ -5366,6 +5366,12 @@ ProcSendEvent(ClientPtr client)
+         client->errorValue = stuff->event.u.u.type;
+         return BadValue;
+     }
++    /* Generic events can have variable size, but SendEvent request holds
++       exactly 32B of event data. */
++    if (stuff->event.u.u.type == GenericEvent) {
++        client->errorValue = stuff->event.u.u.type;
++        return BadValue;
++    }
+     if (stuff->event.u.u.type == ClientMessage &&
+         stuff->event.u.u.detail != 8 &&
+         stuff->event.u.u.detail != 16 && stuff->event.u.u.detail != 32) {
+diff --git a/dix/swapreq.c b/dix/swapreq.c
+index 719e9b81c..67850593b 100644
+--- a/dix/swapreq.c
++++ b/dix/swapreq.c
+@@ -292,6 +292,13 @@ SProcSendEvent(ClientPtr client)
+     swapl(&stuff->destination);
+     swapl(&stuff->eventMask);
+ 
++    /* Generic events can have variable size, but SendEvent request holds
++       exactly 32B of event data. */
++    if (stuff->event.u.u.type == GenericEvent) {
++        client->errorValue = stuff->event.u.u.type;
++        return BadValue;
++    }
++
+     /* Swap event */
+     proc = EventSwapVector[stuff->event.u.u.type & 0177];
+     if (!proc || proc == NotImplemented)        /* no swapping proc; invalid event type? */
+-- 
+2.11.0
+