Date: Sun, 20 May 2018 13:18:47 +0000 (UTC) From: Niclas Zeising <zeising@FreeBSD.org> To: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: svn commit: r470454 - in head/x11-servers/xorg-server: . files Message-ID: <201805201318.w4KDIlTo033390@repo.freebsd.org>
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Author: zeising Date: Sun May 20 13:18:47 2018 New Revision: 470454 URL: https://svnweb.freebsd.org/changeset/ports/470454 Log: x11-servers/xorg-server: Backport security fixes Backport security fixes for CVE-2017-10971 and CVE-2017-10972 (yes, 2017). For some reason this was not done when the vulnerabilities were documented in VuXML, and a typo in the version range in VuXML meant that the entries never matched. This fixes a memory disclosure and a couple of buffer overruns. PR: 220584 Reported by: Vladimir Krstulja MFH: 2018Q2 Security: ab881a74-c016-4e6d-9f7d-68c8e7cedafb Added: head/x11-servers/xorg-server/files/patch-CVE-2017-10971 (contents, props changed) head/x11-servers/xorg-server/files/patch-CVE-2017-10972 (contents, props changed) Modified: head/x11-servers/xorg-server/Makefile Modified: head/x11-servers/xorg-server/Makefile ============================================================================== --- head/x11-servers/xorg-server/Makefile Sun May 20 13:14:18 2018 (r470453) +++ head/x11-servers/xorg-server/Makefile Sun May 20 13:18:47 2018 (r470454) @@ -3,7 +3,7 @@ PORTNAME?= xorg-server PORTVERSION?= 1.18.4 -PORTREVISION?= 6 +PORTREVISION?= 7 PORTEPOCH?= 1 CATEGORIES= x11-servers MASTER_SITES= XORG/individual/xserver Added: head/x11-servers/xorg-server/files/patch-CVE-2017-10971 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/x11-servers/xorg-server/files/patch-CVE-2017-10971 Sun May 20 13:18:47 2018 (r470454) @@ -0,0 +1,163 @@ +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: 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> +--- + dix/events.c | 6 ++++++ + dix/swapreq.c | 7 +++++++ + 2 files changed, 13 insertions(+) + +diff --git a/dix/events.c b/dix/events.c +index 3e3a01e..d3a33ea 100644 +--- dix/events.c ++++ 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 719e9b8..6785059 100644 +--- dix/swapreq.c ++++ 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? */ +-- +cgit v1.1 + +From 8caed4df36b1f802b4992edcfd282cbeeec35d9d Mon Sep 17 00:00:00 2001 +From: Michal Srb <msrb@suse.com> +Date: Wed, 24 May 2017 15:54:41 +0300 +Subject: Xi: Verify all events in ProcXSendExtensionEvent. + +The requirement is that events have type in range +EXTENSION_EVENT_BASE..lastEvent, but it was tested +only for first event of all. + +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> +--- + Xi/sendexev.c | 12 +++++++----- + 1 file changed, 7 insertions(+), 5 deletions(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 1cf118a..5e63bfc 100644 +--- Xi/sendexev.c ++++ Xi/sendexev.c +@@ -117,7 +117,7 @@ SProcXSendExtensionEvent(ClientPtr client) + int + ProcXSendExtensionEvent(ClientPtr client) + { +- int ret; ++ int ret, i; + DeviceIntPtr dev; + xEvent *first; + XEventClass *list; +@@ -141,10 +141,12 @@ ProcXSendExtensionEvent(ClientPtr client) + /* The client's event type must be one defined by an extension. */ + + first = ((xEvent *) &stuff[1]); +- if (!((EXTENSION_EVENT_BASE <= first->u.u.type) && +- (first->u.u.type < lastEvent))) { +- client->errorValue = first->u.u.type; +- return BadValue; ++ for (i = 0; i < stuff->num_events; i++) { ++ if (!((EXTENSION_EVENT_BASE <= first[i].u.u.type) && ++ (first[i].u.u.type < lastEvent))) { ++ client->errorValue = first[i].u.u.type; ++ return BadValue; ++ } + } + + list = (XEventClass *) (first + stuff->num_events); +-- +cgit v1.1 + +From ba336b24052122b136486961c82deac76bbde455 Mon Sep 17 00:00:00 2001 +From: Michal Srb <msrb@suse.com> +Date: Wed, 24 May 2017 15:54:42 +0300 +Subject: Xi: Do not try to swap GenericEvent. + +The SProcXSendExtensionEvent must not attempt to swap GenericEvent because +it is assuming that the event has fixed size and gives the swapping function +xEvent-sized buffer. + +A GenericEvent would be later rejected by ProcXSendExtensionEvent anyway. + +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> +--- + Xi/sendexev.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 5e63bfc..5c2e0fc 100644 +--- Xi/sendexev.c ++++ Xi/sendexev.c +@@ -95,9 +95,17 @@ SProcXSendExtensionEvent(ClientPtr client) + + eventP = (xEvent *) &stuff[1]; + for (i = 0; i < stuff->num_events; i++, eventP++) { ++ if (eventP->u.u.type == GenericEvent) { ++ client->errorValue = eventP->u.u.type; ++ return BadValue; ++ } ++ + proc = EventSwapVector[eventP->u.u.type & 0177]; +- if (proc == NotImplemented) /* no swapping proc; invalid event type? */ ++ /* no swapping proc; invalid event type? */ ++ if (proc == NotImplemented) { ++ client->errorValue = eventP->u.u.type; + return BadValue; ++ } + (*proc) (eventP, &eventT); + *eventP = eventT; + } +-- +cgit v1.1 + Added: head/x11-servers/xorg-server/files/patch-CVE-2017-10972 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/x11-servers/xorg-server/files/patch-CVE-2017-10972 Sun May 20 13:18:47 2018 (r470454) @@ -0,0 +1,38 @@ +From 05442de962d3dc624f79fc1a00eca3ffc5489ced Mon Sep 17 00:00:00 2001 +From: Michal Srb <msrb@suse.com> +Date: Wed, 24 May 2017 15:54:39 +0300 +Subject: Xi: Zero target buffer in SProcXSendExtensionEvent. + +Make sure that the xEvent eventT is initialized with zeros, the same way as +in SProcSendEvent. + +Some event swapping functions do not overwrite all 32 bytes of xEvent +structure, for example XSecurityAuthorizationRevoked. Two cooperating +clients, one swapped and the other not, can send +XSecurityAuthorizationRevoked event to each other to retrieve old stack data +from X server. This can be potentialy misused to go around ASLR or +stack-protector. + +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> +--- + Xi/sendexev.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 11d8202..1cf118a 100644 +--- Xi/sendexev.c ++++ Xi/sendexev.c +@@ -78,7 +78,7 @@ SProcXSendExtensionEvent(ClientPtr client) + { + CARD32 *p; + int i; +- xEvent eventT; ++ xEvent eventT = { .u.u.type = 0 }; + xEvent *eventP; + EventSwapPtr proc; + +-- +cgit v1.1 +
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