From 2015d83dd5dbc6832df9d1082a58b7cc0b9fb0ab Mon Sep 17 00:00:00 2001 From: Peter Korsgaard Date: Mon, 10 Jul 2017 09:07:52 +0200 Subject: [PATCH] xserver_xorg-server: add upstream security fixes for CVE-2017-10971 / 10972 Add upstream patches fixing the following security issues: CVE-2017-10971: The endianess handling for X Events assumed a fixed size of X Event structures and had a specific 32 byte stack buffer for that. However "GenericEvents" can have any size, so if the events were sent in the wrong endianess, this stack buffer could be overflowed easily. So authenticated X users could overflow the stack in the X Server and with the X server usually running as root gaining root prileveges. CVE-2017-10972: An information leak out of the X server due to an uninitialized stack area when swapping event endianess. For more details, see the advisory: http://www.openwall.com/lists/oss-security/2017/07/06/6 Signed-off-by: Peter Korsgaard --- ...t-buffer-in-SProcXSendExtensionEvent.patch | 39 ++++++++++ ...ow-GenericEvent-in-SendEvent-request.patch | 71 +++++++++++++++++++ ...ll-events-in-ProcXSendExtensionEvent.patch | 50 +++++++++++++ ...5-Xi-Do-not-try-to-swap-GenericEvent.patch | 45 ++++++++++++ ...t-buffer-in-SProcXSendExtensionEvent.patch | 39 ++++++++++ ...ow-GenericEvent-in-SendEvent-request.patch | 71 +++++++++++++++++++ ...ll-events-in-ProcXSendExtensionEvent.patch | 50 +++++++++++++ ...5-Xi-Do-not-try-to-swap-GenericEvent.patch | 45 ++++++++++++ ...t-buffer-in-SProcXSendExtensionEvent.patch | 39 ++++++++++ ...ow-GenericEvent-in-SendEvent-request.patch | 71 +++++++++++++++++++ ...ll-events-in-ProcXSendExtensionEvent.patch | 50 +++++++++++++ ...7-Xi-Do-not-try-to-swap-GenericEvent.patch | 45 ++++++++++++ 12 files changed, 615 insertions(+) create mode 100644 package/x11r7/xserver_xorg-server/1.14.7/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.14.7/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch create mode 100644 package/x11r7/xserver_xorg-server/1.14.7/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.14.7/0005-Xi-Do-not-try-to-swap-GenericEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.17.4/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.17.4/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch create mode 100644 package/x11r7/xserver_xorg-server/1.17.4/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.17.4/0005-Xi-Do-not-try-to-swap-GenericEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.19.3/0004-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.19.3/0005-dix-Disallow-GenericEvent-in-SendEvent-request.patch create mode 100644 package/x11r7/xserver_xorg-server/1.19.3/0006-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch create mode 100644 package/x11r7/xserver_xorg-server/1.19.3/0007-Xi-Do-not-try-to-swap-GenericEvent.patch diff --git a/package/x11r7/xserver_xorg-server/1.14.7/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.14.7/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..c15dc9f50c --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.14.7/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch @@ -0,0 +1,39 @@ +From 05442de962d3dc624f79fc1a00eca3ffc5489ced Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:39 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 11d82029f..1cf118ab6 100644 +--- a/Xi/sendexev.c ++++ b/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; + +-- +2.11.0 + 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 +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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + 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 + diff --git a/package/x11r7/xserver_xorg-server/1.14.7/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.14.7/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..2e651006ba --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.14.7/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch @@ -0,0 +1,50 @@ +From 8caed4df36b1f802b4992edcfd282cbeeec35d9d Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:41 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 12 +++++++----- + 1 file changed, 7 insertions(+), 5 deletions(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 1cf118ab6..5e63bfcca 100644 +--- a/Xi/sendexev.c ++++ b/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); +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.14.7/0005-Xi-Do-not-try-to-swap-GenericEvent.patch b/package/x11r7/xserver_xorg-server/1.14.7/0005-Xi-Do-not-try-to-swap-GenericEvent.patch new file mode 100644 index 0000000000..871e7621ed --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.14.7/0005-Xi-Do-not-try-to-swap-GenericEvent.patch @@ -0,0 +1,45 @@ +From ba336b24052122b136486961c82deac76bbde455 Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:42 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 5e63bfcca..5c2e0fc56 100644 +--- a/Xi/sendexev.c ++++ b/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; + } +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.17.4/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.17.4/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..c15dc9f50c --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.17.4/0002-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch @@ -0,0 +1,39 @@ +From 05442de962d3dc624f79fc1a00eca3ffc5489ced Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:39 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 11d82029f..1cf118ab6 100644 +--- a/Xi/sendexev.c ++++ b/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; + +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.17.4/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch b/package/x11r7/xserver_xorg-server/1.17.4/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch new file mode 100644 index 0000000000..12da5f5cba --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.17.4/0003-dix-Disallow-GenericEvent-in-SendEvent-request.patch @@ -0,0 +1,71 @@ +From 215f894965df5fb0bb45b107d84524e700d2073c Mon Sep 17 00:00:00 2001 +From: Michal Srb +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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + 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 + diff --git a/package/x11r7/xserver_xorg-server/1.17.4/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.17.4/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..2e651006ba --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.17.4/0004-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch @@ -0,0 +1,50 @@ +From 8caed4df36b1f802b4992edcfd282cbeeec35d9d Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:41 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 12 +++++++----- + 1 file changed, 7 insertions(+), 5 deletions(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 1cf118ab6..5e63bfcca 100644 +--- a/Xi/sendexev.c ++++ b/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); +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.17.4/0005-Xi-Do-not-try-to-swap-GenericEvent.patch b/package/x11r7/xserver_xorg-server/1.17.4/0005-Xi-Do-not-try-to-swap-GenericEvent.patch new file mode 100644 index 0000000000..871e7621ed --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.17.4/0005-Xi-Do-not-try-to-swap-GenericEvent.patch @@ -0,0 +1,45 @@ +From ba336b24052122b136486961c82deac76bbde455 Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:42 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 5e63bfcca..5c2e0fc56 100644 +--- a/Xi/sendexev.c ++++ b/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; + } +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.19.3/0004-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.19.3/0004-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..c15dc9f50c --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.19.3/0004-Xi-Zero-target-buffer-in-SProcXSendExtensionEvent.patch @@ -0,0 +1,39 @@ +From 05442de962d3dc624f79fc1a00eca3ffc5489ced Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:39 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 11d82029f..1cf118ab6 100644 +--- a/Xi/sendexev.c ++++ b/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; + +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.19.3/0005-dix-Disallow-GenericEvent-in-SendEvent-request.patch b/package/x11r7/xserver_xorg-server/1.19.3/0005-dix-Disallow-GenericEvent-in-SendEvent-request.patch new file mode 100644 index 0000000000..12da5f5cba --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.19.3/0005-dix-Disallow-GenericEvent-in-SendEvent-request.patch @@ -0,0 +1,71 @@ +From 215f894965df5fb0bb45b107d84524e700d2073c Mon Sep 17 00:00:00 2001 +From: Michal Srb +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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + 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 + diff --git a/package/x11r7/xserver_xorg-server/1.19.3/0006-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch b/package/x11r7/xserver_xorg-server/1.19.3/0006-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch new file mode 100644 index 0000000000..2e651006ba --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.19.3/0006-Xi-Verify-all-events-in-ProcXSendExtensionEvent.patch @@ -0,0 +1,50 @@ +From 8caed4df36b1f802b4992edcfd282cbeeec35d9d Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:41 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 12 +++++++----- + 1 file changed, 7 insertions(+), 5 deletions(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 1cf118ab6..5e63bfcca 100644 +--- a/Xi/sendexev.c ++++ b/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); +-- +2.11.0 + diff --git a/package/x11r7/xserver_xorg-server/1.19.3/0007-Xi-Do-not-try-to-swap-GenericEvent.patch b/package/x11r7/xserver_xorg-server/1.19.3/0007-Xi-Do-not-try-to-swap-GenericEvent.patch new file mode 100644 index 0000000000..871e7621ed --- /dev/null +++ b/package/x11r7/xserver_xorg-server/1.19.3/0007-Xi-Do-not-try-to-swap-GenericEvent.patch @@ -0,0 +1,45 @@ +From ba336b24052122b136486961c82deac76bbde455 Mon Sep 17 00:00:00 2001 +From: Michal Srb +Date: Wed, 24 May 2017 15:54:42 +0300 +Subject: [PATCH] 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 +Reviewed-by: Peter Hutterer +Signed-off-by: Peter Hutterer +Signed-off-by: Peter Korsgaard +--- + Xi/sendexev.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +diff --git a/Xi/sendexev.c b/Xi/sendexev.c +index 5e63bfcca..5c2e0fc56 100644 +--- a/Xi/sendexev.c ++++ b/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; + } +-- +2.11.0 + -- 2.30.2