xserver-multidpi/Xi/xiquerydevice.c
Alan Coopersmith 73c63afb93 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>
2014-12-08 18:09:48 -08:00

597 lines
15 KiB
C

/*
* Copyright © 2009 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors: Peter Hutterer
*
*/
/**
* @file Protocol handling for the XIQueryDevice request/reply.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#include "inputstr.h"
#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/extensions/XI2proto.h>
#include "xkbstr.h"
#include "xkbsrv.h"
#include "xserver-properties.h"
#include "exevents.h"
#include "xace.h"
#include "inpututils.h"
#include "xiquerydevice.h"
static Bool ShouldSkipDevice(ClientPtr client, int deviceid, DeviceIntPtr d);
static int
ListDeviceInfo(ClientPtr client, DeviceIntPtr dev, xXIDeviceInfo * info);
static int SizeDeviceInfo(DeviceIntPtr dev);
static void SwapDeviceInfo(DeviceIntPtr dev, xXIDeviceInfo * info);
int
SProcXIQueryDevice(ClientPtr client)
{
REQUEST(xXIQueryDeviceReq);
REQUEST_SIZE_MATCH(xXIQueryDeviceReq);
swaps(&stuff->length);
swaps(&stuff->deviceid);
return ProcXIQueryDevice(client);
}
int
ProcXIQueryDevice(ClientPtr client)
{
xXIQueryDeviceReply rep;
DeviceIntPtr dev = NULL;
int rc = Success;
int i = 0, len = 0;
char *info, *ptr;
Bool *skip = NULL;
REQUEST(xXIQueryDeviceReq);
REQUEST_SIZE_MATCH(xXIQueryDeviceReq);
if (stuff->deviceid != XIAllDevices &&
stuff->deviceid != XIAllMasterDevices) {
rc = dixLookupDevice(&dev, stuff->deviceid, client, DixGetAttrAccess);
if (rc != Success) {
client->errorValue = stuff->deviceid;
return rc;
}
len += SizeDeviceInfo(dev);
}
else {
skip = calloc(sizeof(Bool), inputInfo.numDevices);
if (!skip)
return BadAlloc;
for (dev = inputInfo.devices; dev; dev = dev->next, i++) {
skip[i] = ShouldSkipDevice(client, stuff->deviceid, dev);
if (!skip[i])
len += SizeDeviceInfo(dev);
}
for (dev = inputInfo.off_devices; dev; dev = dev->next, i++) {
skip[i] = ShouldSkipDevice(client, stuff->deviceid, dev);
if (!skip[i])
len += SizeDeviceInfo(dev);
}
}
info = calloc(1, len);
if (!info) {
free(skip);
return BadAlloc;
}
rep = (xXIQueryDeviceReply) {
.repType = X_Reply,
.RepType = X_XIQueryDevice,
.sequenceNumber = client->sequence,
.length = len / 4,
.num_devices = 0
};
ptr = info;
if (dev) {
len = ListDeviceInfo(client, dev, (xXIDeviceInfo *) info);
if (client->swapped)
SwapDeviceInfo(dev, (xXIDeviceInfo *) info);
info += len;
rep.num_devices = 1;
}
else {
i = 0;
for (dev = inputInfo.devices; dev; dev = dev->next, i++) {
if (!skip[i]) {
len = ListDeviceInfo(client, dev, (xXIDeviceInfo *) info);
if (client->swapped)
SwapDeviceInfo(dev, (xXIDeviceInfo *) info);
info += len;
rep.num_devices++;
}
}
for (dev = inputInfo.off_devices; dev; dev = dev->next, i++) {
if (!skip[i]) {
len = ListDeviceInfo(client, dev, (xXIDeviceInfo *) info);
if (client->swapped)
SwapDeviceInfo(dev, (xXIDeviceInfo *) info);
info += len;
rep.num_devices++;
}
}
}
len = rep.length * 4;
WriteReplyToClient(client, sizeof(xXIQueryDeviceReply), &rep);
WriteToClient(client, len, ptr);
free(ptr);
free(skip);
return rc;
}
void
SRepXIQueryDevice(ClientPtr client, int size, xXIQueryDeviceReply * rep)
{
swaps(&rep->sequenceNumber);
swapl(&rep->length);
swaps(&rep->num_devices);
/* Device info is already swapped, see ProcXIQueryDevice */
WriteToClient(client, size, rep);
}
/**
* @return Whether the device should be included in the returned list.
*/
static Bool
ShouldSkipDevice(ClientPtr client, int deviceid, DeviceIntPtr dev)
{
/* if all devices are not being queried, only master devices are */
if (deviceid == XIAllDevices || IsMaster(dev)) {
int rc = XaceHook(XACE_DEVICE_ACCESS, client, dev, DixGetAttrAccess);
if (rc == Success)
return FALSE;
}
return TRUE;
}
/**
* @return The number of bytes needed to store this device's xXIDeviceInfo
* (and its classes).
*/
static int
SizeDeviceInfo(DeviceIntPtr dev)
{
int len = sizeof(xXIDeviceInfo);
/* 4-padded name */
len += pad_to_int32(strlen(dev->name));
return len + SizeDeviceClasses(dev);
}
/*
* @return The number of bytes needed to store this device's classes.
*/
int
SizeDeviceClasses(DeviceIntPtr dev)
{
int len = 0;
if (dev->button) {
len += sizeof(xXIButtonInfo);
len += dev->button->numButtons * sizeof(Atom);
len += pad_to_int32(bits_to_bytes(dev->button->numButtons));
}
if (dev->key) {
XkbDescPtr xkb = dev->key->xkbInfo->desc;
len += sizeof(xXIKeyInfo);
len += (xkb->max_key_code - xkb->min_key_code + 1) * sizeof(uint32_t);
}
if (dev->valuator) {
int i;
len += (sizeof(xXIValuatorInfo)) * dev->valuator->numAxes;
for (i = 0; i < dev->valuator->numAxes; i++) {
if (dev->valuator->axes[i].scroll.type != SCROLL_TYPE_NONE)
len += sizeof(xXIScrollInfo);
}
}
if (dev->touch)
len += sizeof(xXITouchInfo);
return len;
}
/**
* Write button information into info.
* @return Number of bytes written into info.
*/
int
ListButtonInfo(DeviceIntPtr dev, xXIButtonInfo * info, Bool reportState)
{
unsigned char *bits;
int mask_len;
int i;
if (!dev || !dev->button)
return 0;
mask_len = bytes_to_int32(bits_to_bytes(dev->button->numButtons));
info->type = ButtonClass;
info->num_buttons = dev->button->numButtons;
info->length = bytes_to_int32(sizeof(xXIButtonInfo)) +
info->num_buttons + mask_len;
info->sourceid = dev->button->sourceid;
bits = (unsigned char *) &info[1];
memset(bits, 0, mask_len * 4);
if (reportState)
for (i = 0; i < dev->button->numButtons; i++)
if (BitIsOn(dev->button->down, i))
SetBit(bits, i);
bits += mask_len * 4;
memcpy(bits, dev->button->labels, dev->button->numButtons * sizeof(Atom));
return info->length * 4;
}
static void
SwapButtonInfo(DeviceIntPtr dev, xXIButtonInfo * info)
{
Atom *btn;
int i;
swaps(&info->type);
swaps(&info->length);
swaps(&info->sourceid);
for (i = 0, btn = (Atom *) &info[1]; i < info->num_buttons; i++, btn++)
swapl(btn);
swaps(&info->num_buttons);
}
/**
* Write key information into info.
* @return Number of bytes written into info.
*/
int
ListKeyInfo(DeviceIntPtr dev, xXIKeyInfo * info)
{
int i;
XkbDescPtr xkb = dev->key->xkbInfo->desc;
uint32_t *kc;
info->type = KeyClass;
info->num_keycodes = xkb->max_key_code - xkb->min_key_code + 1;
info->length = sizeof(xXIKeyInfo) / 4 + info->num_keycodes;
info->sourceid = dev->key->sourceid;
kc = (uint32_t *) &info[1];
for (i = xkb->min_key_code; i <= xkb->max_key_code; i++, kc++)
*kc = i;
return info->length * 4;
}
static void
SwapKeyInfo(DeviceIntPtr dev, xXIKeyInfo * info)
{
uint32_t *key;
int i;
swaps(&info->type);
swaps(&info->length);
swaps(&info->sourceid);
for (i = 0, key = (uint32_t *) &info[1]; i < info->num_keycodes;
i++, key++)
swapl(key);
swaps(&info->num_keycodes);
}
/**
* List axis information for the given axis.
*
* @return The number of bytes written into info.
*/
int
ListValuatorInfo(DeviceIntPtr dev, xXIValuatorInfo * info, int axisnumber,
Bool reportState)
{
ValuatorClassPtr v = dev->valuator;
info->type = ValuatorClass;
info->length = sizeof(xXIValuatorInfo) / 4;
info->label = v->axes[axisnumber].label;
info->min.integral = v->axes[axisnumber].min_value;
info->min.frac = 0;
info->max.integral = v->axes[axisnumber].max_value;
info->max.frac = 0;
info->value = double_to_fp3232(v->axisVal[axisnumber]);
info->resolution = v->axes[axisnumber].resolution;
info->number = axisnumber;
info->mode = valuator_get_mode(dev, axisnumber);
info->sourceid = v->sourceid;
if (!reportState)
info->value = info->min;
return info->length * 4;
}
static void
SwapValuatorInfo(DeviceIntPtr dev, xXIValuatorInfo * info)
{
swaps(&info->type);
swaps(&info->length);
swapl(&info->label);
swapl(&info->min.integral);
swapl(&info->min.frac);
swapl(&info->max.integral);
swapl(&info->max.frac);
swaps(&info->number);
swaps(&info->sourceid);
}
int
ListScrollInfo(DeviceIntPtr dev, xXIScrollInfo * info, int axisnumber)
{
ValuatorClassPtr v = dev->valuator;
AxisInfoPtr axis = &v->axes[axisnumber];
if (axis->scroll.type == SCROLL_TYPE_NONE)
return 0;
info->type = XIScrollClass;
info->length = sizeof(xXIScrollInfo) / 4;
info->number = axisnumber;
switch (axis->scroll.type) {
case SCROLL_TYPE_VERTICAL:
info->scroll_type = XIScrollTypeVertical;
break;
case SCROLL_TYPE_HORIZONTAL:
info->scroll_type = XIScrollTypeHorizontal;
break;
default:
ErrorF("[Xi] Unknown scroll type %d. This is a bug.\n",
axis->scroll.type);
break;
}
info->increment = double_to_fp3232(axis->scroll.increment);
info->sourceid = v->sourceid;
info->flags = 0;
if (axis->scroll.flags & SCROLL_FLAG_DONT_EMULATE)
info->flags |= XIScrollFlagNoEmulation;
if (axis->scroll.flags & SCROLL_FLAG_PREFERRED)
info->flags |= XIScrollFlagPreferred;
return info->length * 4;
}
static void
SwapScrollInfo(DeviceIntPtr dev, xXIScrollInfo * info)
{
swaps(&info->type);
swaps(&info->length);
swaps(&info->number);
swaps(&info->sourceid);
swaps(&info->scroll_type);
swapl(&info->increment.integral);
swapl(&info->increment.frac);
}
/**
* List multitouch information
*
* @return The number of bytes written into info.
*/
int
ListTouchInfo(DeviceIntPtr dev, xXITouchInfo * touch)
{
touch->type = XITouchClass;
touch->length = sizeof(xXITouchInfo) >> 2;
touch->sourceid = dev->touch->sourceid;
touch->mode = dev->touch->mode;
touch->num_touches = dev->touch->num_touches;
return touch->length << 2;
}
static void
SwapTouchInfo(DeviceIntPtr dev, xXITouchInfo * touch)
{
swaps(&touch->type);
swaps(&touch->length);
swaps(&touch->sourceid);
}
int
GetDeviceUse(DeviceIntPtr dev, uint16_t * attachment)
{
DeviceIntPtr master = GetMaster(dev, MASTER_ATTACHED);
int use;
if (IsMaster(dev)) {
DeviceIntPtr paired = GetPairedDevice(dev);
use = IsPointerDevice(dev) ? XIMasterPointer : XIMasterKeyboard;
*attachment = (paired ? paired->id : 0);
}
else if (!IsFloating(dev)) {
use = IsPointerDevice(master) ? XISlavePointer : XISlaveKeyboard;
*attachment = master->id;
}
else
use = XIFloatingSlave;
return use;
}
/**
* Write the info for device dev into the buffer pointed to by info.
*
* @return The number of bytes used.
*/
static int
ListDeviceInfo(ClientPtr client, DeviceIntPtr dev, xXIDeviceInfo * info)
{
char *any = (char *) &info[1];
int len = 0, total_len = 0;
info->deviceid = dev->id;
info->use = GetDeviceUse(dev, &info->attachment);
info->num_classes = 0;
info->name_len = strlen(dev->name);
info->enabled = dev->enabled;
total_len = sizeof(xXIDeviceInfo);
len = pad_to_int32(info->name_len);
memset(any, 0, len);
strncpy(any, dev->name, info->name_len);
any += len;
total_len += len;
total_len += ListDeviceClasses(client, dev, any, &info->num_classes);
return total_len;
}
/**
* Write the class info of the device into the memory pointed to by any, set
* nclasses to the number of classes in total and return the number of bytes
* written.
*/
int
ListDeviceClasses(ClientPtr client, DeviceIntPtr dev,
char *any, uint16_t * nclasses)
{
int total_len = 0;
int len;
int i;
int rc;
/* Check if the current device state should be suppressed */
rc = XaceHook(XACE_DEVICE_ACCESS, client, dev, DixReadAccess);
if (dev->button) {
(*nclasses)++;
len = ListButtonInfo(dev, (xXIButtonInfo *) any, rc == Success);
any += len;
total_len += len;
}
if (dev->key) {
(*nclasses)++;
len = ListKeyInfo(dev, (xXIKeyInfo *) any);
any += len;
total_len += len;
}
for (i = 0; dev->valuator && i < dev->valuator->numAxes; i++) {
(*nclasses)++;
len = ListValuatorInfo(dev, (xXIValuatorInfo *) any, i, rc == Success);
any += len;
total_len += len;
}
for (i = 0; dev->valuator && i < dev->valuator->numAxes; i++) {
len = ListScrollInfo(dev, (xXIScrollInfo *) any, i);
if (len)
(*nclasses)++;
any += len;
total_len += len;
}
if (dev->touch) {
(*nclasses)++;
len = ListTouchInfo(dev, (xXITouchInfo *) any);
any += len;
total_len += len;
}
return total_len;
}
static void
SwapDeviceInfo(DeviceIntPtr dev, xXIDeviceInfo * info)
{
char *any = (char *) &info[1];
int i;
/* Skip over name */
any += pad_to_int32(info->name_len);
for (i = 0; i < info->num_classes; i++) {
int len = ((xXIAnyInfo *) any)->length;
switch (((xXIAnyInfo *) any)->type) {
case XIButtonClass:
SwapButtonInfo(dev, (xXIButtonInfo *) any);
break;
case XIKeyClass:
SwapKeyInfo(dev, (xXIKeyInfo *) any);
break;
case XIValuatorClass:
SwapValuatorInfo(dev, (xXIValuatorInfo *) any);
break;
case XIScrollClass:
SwapScrollInfo(dev, (xXIScrollInfo *) any);
break;
case XITouchClass:
SwapTouchInfo(dev, (xXITouchInfo *) any);
break;
}
any += len * 4;
}
swaps(&info->deviceid);
swaps(&info->use);
swaps(&info->attachment);
swaps(&info->num_classes);
swaps(&info->name_len);
}