From 757fe009c45278807d6951d6380292de9133f0f8 Mon Sep 17 00:00:00 2001
From: Alan Coopersmith <alan.coopersmith@oracle.com>
Date: Sun, 26 Jan 2014 10:54:41 -0800
Subject: [PATCH 08/33] Xi: unvalidated lengths in Xinput extension
[CVE-2014-8095]
Multiple functions in the Xinput extension handling of requests from
clients failed to check that the length of the request sent by the
client was large enough to perform all the required operations and
thus could read or write to memory outside the bounds of the request
buffer.
This commit includes the creation of a new REQUEST_AT_LEAST_EXTRA_SIZE
macro in include/dix.h for the common case of needing to ensure a
request is large enough to include both the request itself and a
minimum amount of extra data following the request header.
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Fedora X Ninjas <x@fedoraproject.org>
---
Xi/chgdctl.c | 8 ++++++--
Xi/chgfctl.c | 2 ++
Xi/sendexev.c | 3 +++
Xi/xiallowev.c | 2 ++
Xi/xichangecursor.c | 2 +-
Xi/xichangehierarchy.c | 35 ++++++++++++++++++++++++++++++++---
Xi/xigetclientpointer.c | 1 +
Xi/xigrabdev.c | 9 ++++++++-
Xi/xipassivegrab.c | 12 ++++++++++--
Xi/xiproperty.c | 14 ++++++--------
Xi/xiquerydevice.c | 1 +
Xi/xiquerypointer.c | 2 ++
Xi/xiselectev.c | 8 ++++++++
Xi/xisetclientpointer.c | 3 ++-
Xi/xisetdevfocus.c | 4 ++++
Xi/xiwarppointer.c | 2 ++
include/dix.h | 4 ++++
17 files changed, 94 insertions(+), 18 deletions(-)
diff --git a/Xi/chgdctl.c b/Xi/chgdctl.c
index d078aa2..b3ee867 100644
--- a/Xi/chgdctl.c
+++ b/Xi/chgdctl.c
@@ -78,7 +78,7 @@ SProcXChangeDeviceControl(ClientPtr client)
REQUEST(xChangeDeviceControlReq);
swaps(&stuff->length);
- REQUEST_AT_LEAST_SIZE(xChangeDeviceControlReq);
+ REQUEST_AT_LEAST_EXTRA_SIZE(xChangeDeviceControlReq, sizeof(xDeviceCtl));
swaps(&stuff->control);
ctl = (xDeviceCtl *) &stuff[1];
swaps(&ctl->control);
@@ -115,7 +115,7 @@ ProcXChangeDeviceControl(ClientPtr client)
xDeviceEnableCtl *e;
REQUEST(xChangeDeviceControlReq);
- REQUEST_AT_LEAST_SIZE(xChangeDeviceControlReq);
+ REQUEST_AT_LEAST_EXTRA_SIZE(xChangeDeviceControlReq, sizeof(xDeviceCtl));
len = stuff->length - bytes_to_int32(sizeof(xChangeDeviceControlReq));
ret = dixLookupDevice(&dev, stuff->deviceid, client, DixManageAccess);
@@ -192,6 +192,10 @@ ProcXChangeDeviceControl(ClientPtr client)
break;
case DEVICE_ENABLE:
e = (xDeviceEnableCtl *) &stuff[1];
+ if ((len != bytes_to_int32(sizeof(xDeviceEnableCtl)))) {
+ ret = BadLength;
+ goto out;
+ }
if (IsXTestDevice(dev, NULL))
status = !Success;
diff --git a/Xi/chgfctl.c b/Xi/chgfctl.c
index 6dcf60c..224c2ba 100644
--- a/Xi/chgfctl.c
+++ b/Xi/chgfctl.c
@@ -467,6 +467,8 @@ ProcXChangeFeedbackControl(ClientPtr client)
xStringFeedbackCtl *f = ((xStringFeedbackCtl *) &stuff[1]);
if (client->swapped) {
+ if (len < bytes_to_int32(sizeof(xStringFeedbackCtl)))
+ return BadLength;
swaps(&f->num_keysyms);
}
if (len !=
diff --git a/Xi/sendexev.c b/Xi/sendexev.c
index 3c21386..183f88d 100644
--- a/Xi/sendexev.c
+++ b/Xi/sendexev.c
@@ -135,6 +135,9 @@ ProcXSendExtensionEvent(ClientPtr client)
if (ret != Success)
return ret;
+ if (stuff->num_events == 0)
+ return ret;
+
/* The client's event type must be one defined by an extension. */
first = ((xEvent *) &stuff[1]);
diff --git a/Xi/xiallowev.c b/Xi/xiallowev.c
index ebef233..ca263ef 100644
--- a/Xi/xiallowev.c
+++ b/Xi/xiallowev.c
@@ -48,6 +48,7 @@ int
SProcXIAllowEvents(ClientPtr client)
{
REQUEST(xXIAllowEventsReq);
+ REQUEST_AT_LEAST_SIZE(xXIAllowEventsReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
@@ -55,6 +56,7 @@ SProcXIAllowEvents(ClientPtr client)
if (stuff->length > 3) {
xXI2_2AllowEventsReq *req_xi22 = (xXI2_2AllowEventsReq *) stuff;
+ REQUEST_AT_LEAST_SIZE(xXI2_2AllowEventsReq);
swapl(&req_xi22->touchid);
swapl(&req_xi22->grab_window);
}
diff --git a/Xi/xichangecursor.c b/Xi/xichangecursor.c
index 0be6bc0..33e9e9c 100644
--- a/Xi/xichangecursor.c
+++ b/Xi/xichangecursor.c
@@ -57,11 +57,11 @@ int
SProcXIChangeCursor(ClientPtr client)
{
REQUEST(xXIChangeCursorReq);
+ REQUEST_SIZE_MATCH(xXIChangeCursorReq);
swaps(&stuff->length);
swapl(&stuff->win);
swapl(&stuff->cursor);
swaps(&stuff->deviceid);
- REQUEST_SIZE_MATCH(xXIChangeCursorReq);
return (ProcXIChangeCursor(client));
}
diff --git a/Xi/xichangehierarchy.c b/Xi/xichangehierarchy.c
index e2f4b8a..8e3415b 100644
--- a/Xi/xichangehierarchy.c
+++ b/Xi/xichangehierarchy.c
@@ -407,7 +407,7 @@ int
ProcXIChangeHierarchy(ClientPtr client)
{
xXIAnyHierarchyChangeInfo *any;
- int required_len = sizeof(xXIChangeHierarchyReq);
+ size_t len; /* length of data remaining in request */
int rc = Success;
int flags[MAXDEVICES] = { 0 };
@@ -417,21 +417,46 @@ ProcXIChangeHierarchy(ClientPtr client)
if (!stuff->num_changes)
return rc;
+ if (stuff->length > (INT_MAX >> 2))
+ return BadAlloc;
+ len = (stuff->length << 2) - sizeof(xXIAnyHierarchyChangeInfo);
+
any = (xXIAnyHierarchyChangeInfo *) &stuff[1];
while (stuff->num_changes--) {
+ if (len < sizeof(xXIAnyHierarchyChangeInfo)) {
+ rc = BadLength;
+ goto unwind;
+ }
+
SWAPIF(swaps(&any->type));
SWAPIF(swaps(&any->length));
- required_len += any->length;
- if ((stuff->length * 4) < required_len)
+ if ((any->length > (INT_MAX >> 2)) || (len < (any->length << 2)))
return BadLength;
+#define CHANGE_SIZE_MATCH(type) \
+ do { \
+ if ((len < sizeof(type)) || (any->length != (sizeof(type) >> 2))) { \
+ rc = BadLength; \
+ goto unwind; \
+ } \
+ } while(0)
+
switch (any->type) {
case XIAddMaster:
{
xXIAddMasterInfo *c = (xXIAddMasterInfo *) any;
+ /* Variable length, due to appended name string */
+ if (len < sizeof(xXIAddMasterInfo)) {
+ rc = BadLength;
+ goto unwind;
+ }
SWAPIF(swaps(&c->name_len));
+ if (c->name_len > (len - sizeof(xXIAddMasterInfo))) {
+ rc = BadLength;
+ goto unwind;
+ }
rc = add_master(client, c, flags);
if (rc != Success)
@@ -442,6 +467,7 @@ ProcXIChangeHierarchy(ClientPtr client)
{
xXIRemoveMasterInfo *r = (xXIRemoveMasterInfo *) any;
+ CHANGE_SIZE_MATCH(xXIRemoveMasterInfo);
rc = remove_master(client, r, flags);
if (rc != Success)
goto unwind;
@@ -451,6 +477,7 @@ ProcXIChangeHierarchy(ClientPtr client)
{
xXIDetachSlaveInfo *c = (xXIDetachSlaveInfo *) any;
+ CHANGE_SIZE_MATCH(xXIDetachSlaveInfo);
rc = detach_slave(client, c, flags);
if (rc != Success)
goto unwind;
@@ -460,6 +487,7 @@ ProcXIChangeHierarchy(ClientPtr client)
{
xXIAttachSlaveInfo *c = (xXIAttachSlaveInfo *) any;
+ CHANGE_SIZE_MATCH(xXIAttachSlaveInfo);
rc = attach_slave(client, c, flags);
if (rc != Success)
goto unwind;
@@ -467,6 +495,7 @@ ProcXIChangeHierarchy(ClientPtr client)
break;
}
+ len -= any->length * 4;
any = (xXIAnyHierarchyChangeInfo *) ((char *) any + any->length * 4);
}
diff --git a/Xi/xigetclientpointer.c b/Xi/xigetclientpointer.c
index 3c90d58..306dd39 100644
--- a/Xi/xigetclientpointer.c
+++ b/Xi/xigetclientpointer.c
@@ -50,6 +50,7 @@ int
SProcXIGetClientPointer(ClientPtr client)
{
REQUEST(xXIGetClientPointerReq);
+ REQUEST_SIZE_MATCH(xXIGetClientPointerReq);
swaps(&stuff->length);
swapl(&stuff->win);
diff --git a/Xi/xigrabdev.c b/Xi/xigrabdev.c
index 63d95bc..e2a2ae3 100644
--- a/Xi/xigrabdev.c
+++ b/Xi/xigrabdev.c
@@ -47,6 +47,11 @@ int
SProcXIGrabDevice(ClientPtr client)
{
REQUEST(xXIGrabDeviceReq);
+ /*
+ * Check here for at least the length of the struct we swap, then
+ * let ProcXIGrabDevice check the full size after we swap mask_len.
+ */
+ REQUEST_AT_LEAST_SIZE(xXIGrabDeviceReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
@@ -71,7 +76,7 @@ ProcXIGrabDevice(ClientPtr client)
unsigned int pointer_mode;
REQUEST(xXIGrabDeviceReq);
- REQUEST_AT_LEAST_SIZE(xXIGrabDeviceReq);
+ REQUEST_FIXED_SIZE(xXIGrabDeviceReq, ((size_t) stuff->mask_len) * 4);
ret = dixLookupDevice(&dev, stuff->deviceid, client, DixGrabAccess);
if (ret != Success)
@@ -131,6 +136,7 @@ int
SProcXIUngrabDevice(ClientPtr client)
{
REQUEST(xXIUngrabDeviceReq);
+ REQUEST_SIZE_MATCH(xXIUngrabDeviceReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
@@ -148,6 +154,7 @@ ProcXIUngrabDevice(ClientPtr client)
TimeStamp time;
REQUEST(xXIUngrabDeviceReq);
+ REQUEST_SIZE_MATCH(xXIUngrabDeviceReq);
ret = dixLookupDevice(&dev, stuff->deviceid, client, DixGetAttrAccess);
if (ret != Success)
diff --git a/Xi/xipassivegrab.c b/Xi/xipassivegrab.c
index eccec0a..a714a44 100644
--- a/Xi/xipassivegrab.c
+++ b/Xi/xipassivegrab.c
@@ -53,6 +53,7 @@ SProcXIPassiveGrabDevice(ClientPtr client)
uint32_t *mods;
REQUEST(xXIPassiveGrabDeviceReq);
+ REQUEST_AT_LEAST_SIZE(xXIPassiveGrabDeviceReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
@@ -63,6 +64,8 @@ SProcXIPassiveGrabDevice(ClientPtr client)
swaps(&stuff->mask_len);
swaps(&stuff->num_modifiers);
+ REQUEST_FIXED_SIZE(xXIPassiveGrabDeviceReq,
+ ((uint32_t) stuff->mask_len + stuff->num_modifiers) *4);
mods = (uint32_t *) &stuff[1];
for (i = 0; i < stuff->num_modifiers; i++, mods++) {
@@ -92,7 +95,8 @@ ProcXIPassiveGrabDevice(ClientPtr client)
int mask_len;
REQUEST(xXIPassiveGrabDeviceReq);
- REQUEST_AT_LEAST_SIZE(xXIPassiveGrabDeviceReq);
+ REQUEST_FIXED_SIZE(xXIPassiveGrabDeviceReq,
+ ((uint32_t) stuff->mask_len + stuff->num_modifiers) * 4);
if (stuff->deviceid == XIAllDevices)
dev = inputInfo.all_devices;
@@ -248,6 +252,7 @@ SProcXIPassiveUngrabDevice(ClientPtr client)
uint32_t *modifiers;
REQUEST(xXIPassiveUngrabDeviceReq);
+ REQUEST_AT_LEAST_SIZE(xXIPassiveUngrabDeviceReq);
swaps(&stuff->length);
swapl(&stuff->grab_window);
@@ -255,6 +260,8 @@ SProcXIPassiveUngrabDevice(ClientPtr client)
swapl(&stuff->detail);
swaps(&stuff->num_modifiers);
+ REQUEST_FIXED_SIZE(xXIPassiveUngrabDeviceReq,
+ ((uint32_t) stuff->num_modifiers) << 2);
modifiers = (uint32_t *) &stuff[1];
for (i = 0; i < stuff->num_modifiers; i++, modifiers++)
@@ -273,7 +280,8 @@ ProcXIPassiveUngrabDevice(ClientPtr client)
int i, rc;
REQUEST(xXIPassiveUngrabDeviceReq);
- REQUEST_AT_LEAST_SIZE(xXIPassiveUngrabDeviceReq);
+ REQUEST_FIXED_SIZE(xXIPassiveUngrabDeviceReq,
+ ((uint32_t) stuff->num_modifiers) << 2);
if (stuff->deviceid == XIAllDevices)
dev = inputInfo.all_devices;
diff --git a/Xi/xiproperty.c b/Xi/xiproperty.c
index 796ba09..c99e282 100644
--- a/Xi/xiproperty.c
+++ b/Xi/xiproperty.c
@@ -1013,10 +1013,9 @@ int
SProcXListDeviceProperties(ClientPtr client)
{
REQUEST(xListDevicePropertiesReq);
+ REQUEST_SIZE_MATCH(xListDevicePropertiesReq);
swaps(&stuff->length);
-
- REQUEST_SIZE_MATCH(xListDevicePropertiesReq);
return (ProcXListDeviceProperties(client));
}
@@ -1037,10 +1036,10 @@ int
SProcXDeleteDeviceProperty(ClientPtr client)
{
REQUEST(xDeleteDevicePropertyReq);
+ REQUEST_SIZE_MATCH(xDeleteDevicePropertyReq);
swaps(&stuff->length);
swapl(&stuff->property);
- REQUEST_SIZE_MATCH(xDeleteDevicePropertyReq);
return (ProcXDeleteDeviceProperty(client));
}
@@ -1048,13 +1047,13 @@ int
SProcXGetDeviceProperty(ClientPtr client)
{
REQUEST(xGetDevicePropertyReq);
+ REQUEST_SIZE_MATCH(xGetDevicePropertyReq);
swaps(&stuff->length);
swapl(&stuff->property);
swapl(&stuff->type);
swapl(&stuff->longOffset);
swapl(&stuff->longLength);
- REQUEST_SIZE_MATCH(xGetDevicePropertyReq);
return (ProcXGetDeviceProperty(client));
}
@@ -1253,11 +1252,10 @@ int
SProcXIListProperties(ClientPtr client)
{
REQUEST(xXIListPropertiesReq);
+ REQUEST_SIZE_MATCH(xXIListPropertiesReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
-
- REQUEST_SIZE_MATCH(xXIListPropertiesReq);
return (ProcXIListProperties(client));
}
@@ -1279,11 +1277,11 @@ int
SProcXIDeleteProperty(ClientPtr client)
{
REQUEST(xXIDeletePropertyReq);
+ REQUEST_SIZE_MATCH(xXIDeletePropertyReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
swapl(&stuff->property);
- REQUEST_SIZE_MATCH(xXIDeletePropertyReq);
return (ProcXIDeleteProperty(client));
}
@@ -1291,6 +1289,7 @@ int
SProcXIGetProperty(ClientPtr client)
{
REQUEST(xXIGetPropertyReq);
+ REQUEST_SIZE_MATCH(xXIGetPropertyReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
@@ -1298,7 +1297,6 @@ SProcXIGetProperty(ClientPtr client)
swapl(&stuff->type);
swapl(&stuff->offset);
swapl(&stuff->len);
- REQUEST_SIZE_MATCH(xXIGetPropertyReq);
return (ProcXIGetProperty(client));
}
diff --git a/Xi/xiquerydevice.c b/Xi/xiquerydevice.c
index 4e544f0..67a9a4f 100644
--- a/Xi/xiquerydevice.c
+++ b/Xi/xiquerydevice.c
@@ -54,6 +54,7 @@ int
SProcXIQueryDevice(ClientPtr client)
{
REQUEST(xXIQueryDeviceReq);
+ REQUEST_SIZE_MATCH(xXIQueryDeviceReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
diff --git a/Xi/xiquerypointer.c b/Xi/xiquerypointer.c
index e9bdd42..7ec0c85 100644
--- a/Xi/xiquerypointer.c
+++ b/Xi/xiquerypointer.c
@@ -63,6 +63,8 @@ int
SProcXIQueryPointer(ClientPtr client)
{
REQUEST(xXIQueryPointerReq);
+ REQUEST_SIZE_MATCH(xXIQueryPointerReq);
+
swaps(&stuff->length);
swaps(&stuff->deviceid);
swapl(&stuff->win);
diff --git a/Xi/xiselectev.c b/Xi/xiselectev.c
index 45a996e..168579f 100644
--- a/Xi/xiselectev.c
+++ b/Xi/xiselectev.c
@@ -114,6 +114,7 @@ int
SProcXISelectEvents(ClientPtr client)
{
int i;
+ int len;
xXIEventMask *evmask;
REQUEST(xXISelectEventsReq);
@@ -122,10 +123,17 @@ SProcXISelectEvents(ClientPtr client)
swapl(&stuff->win);
swaps(&stuff->num_masks);
+ len = stuff->length - bytes_to_int32(sizeof(xXISelectEventsReq));
evmask = (xXIEventMask *) &stuff[1];
for (i = 0; i < stuff->num_masks; i++) {
+ if (len < bytes_to_int32(sizeof(xXIEventMask)))
+ return BadLength;
+ len -= bytes_to_int32(sizeof(xXIEventMask));
swaps(&evmask->deviceid);
swaps(&evmask->mask_len);
+ if (len < evmask->mask_len)
+ return BadLength;
+ len -= evmask->mask_len;
evmask =
(xXIEventMask *) (((char *) &evmask[1]) + evmask->mask_len * 4);
}
diff --git a/Xi/xisetclientpointer.c b/Xi/xisetclientpointer.c
index 38ff51e..24d4a53 100644
--- a/Xi/xisetclientpointer.c
+++ b/Xi/xisetclientpointer.c
@@ -51,10 +51,11 @@ int
SProcXISetClientPointer(ClientPtr client)
{
REQUEST(xXISetClientPointerReq);
+ REQUEST_SIZE_MATCH(xXISetClientPointerReq);
+
swaps(&stuff->length);
swapl(&stuff->win);
swaps(&stuff->deviceid);
- REQUEST_SIZE_MATCH(xXISetClientPointerReq);
return (ProcXISetClientPointer(client));
}
diff --git a/Xi/xisetdevfocus.c b/Xi/xisetdevfocus.c
index 372ec24..96a9a16 100644
--- a/Xi/xisetdevfocus.c
+++ b/Xi/xisetdevfocus.c
@@ -44,6 +44,8 @@ int
SProcXISetFocus(ClientPtr client)
{
REQUEST(xXISetFocusReq);
+ REQUEST_AT_LEAST_SIZE(xXISetFocusReq);
+
swaps(&stuff->length);
swaps(&stuff->deviceid);
swapl(&stuff->focus);
@@ -56,6 +58,8 @@ int
SProcXIGetFocus(ClientPtr client)
{
REQUEST(xXIGetFocusReq);
+ REQUEST_AT_LEAST_SIZE(xXIGetFocusReq);
+
swaps(&stuff->length);
swaps(&stuff->deviceid);
diff --git a/Xi/xiwarppointer.c b/Xi/xiwarppointer.c
index 3f051f7..780758a 100644
--- a/Xi/xiwarppointer.c
+++ b/Xi/xiwarppointer.c
@@ -56,6 +56,8 @@ int
SProcXIWarpPointer(ClientPtr client)
{
REQUEST(xXIWarpPointerReq);
+ REQUEST_SIZE_MATCH(xXIWarpPointerReq);
+
swaps(&stuff->length);
swapl(&stuff->src_win);
swapl(&stuff->dst_win);
diff --git a/include/dix.h b/include/dix.h
index 7c36932..72adad3 100644
--- a/include/dix.h
+++ b/include/dix.h
@@ -74,6 +74,10 @@ SOFTWARE.
if ((sizeof(req) >> 2) > client->req_len )\
return(BadLength)
+#define REQUEST_AT_LEAST_EXTRA_SIZE(req, extra) \
+ if (((sizeof(req) + ((uint64_t) extra)) >> 2) > client->req_len ) \
+ return(BadLength)
+
#define REQUEST_FIXED_SIZE(req, n)\
if (((sizeof(req) >> 2) > client->req_len) || \
((n >> 2) >= client->req_len) || \
--
1.9.3