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IABSD.fr/xenocara/xserver/Xi/chgfctl.c

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  • Author : matthieu
    Date : 2021-04-13 14:11:12
    Hash : e26c45de
    Message : Fix XChangeFeedbackControl() request underflow. CVE-2021-3472 / ZDI-CAN-1259 Reported by Jan-Niklas Sohn via Trend Micro.

  • xserver/Xi/chgfctl.c
  • /************************************************************
    
    Copyright 1989, 1998  The Open Group
    
    Permission to use, copy, modify, distribute, and sell this software and its
    documentation for any purpose is hereby granted without fee, provided that
    the above copyright notice appear in all copies and that both that
    copyright notice and this permission notice appear in supporting
    documentation.
    
    The above copyright notice and this permission notice 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
    OPEN GROUP 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.
    
    Except as contained in this notice, the name of The Open Group shall not be
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from The Open Group.
    
    Copyright 1989 by Hewlett-Packard Company, Palo Alto, California.
    
    			All Rights Reserved
    
    Permission to use, copy, modify, and distribute this software and its
    documentation for any purpose and without fee is hereby granted,
    provided that the above copyright notice appear in all copies and that
    both that copyright notice and this permission notice appear in
    supporting documentation, and that the name of Hewlett-Packard not be
    used in advertising or publicity pertaining to distribution of the
    software without specific, written prior permission.
    
    HEWLETT-PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
    ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
    HEWLETT-PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
    ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
    WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
    SOFTWARE.
    
    ********************************************************/
    
    /********************************************************************
     *
     *  Change feedback control attributes for an extension device.
     *
     */
    
    #ifdef HAVE_DIX_CONFIG_H
    #include <dix-config.h>
    #endif
    
    #include "inputstr.h"           /* DeviceIntPtr      */
    #include <X11/extensions/XI.h>
    #include <X11/extensions/XIproto.h>     /* control constants */
    
    #include "exglobals.h"
    
    #include "chgfctl.h"
    
    #define DO_ALL    (-1)
    
    /***********************************************************************
     *
     * This procedure changes the control attributes for an extension device,
     * for clients on machines with a different byte ordering than the server.
     *
     */
    
    int _X_COLD
    SProcXChangeFeedbackControl(ClientPtr client)
    {
        REQUEST(xChangeFeedbackControlReq);
        swaps(&stuff->length);
        REQUEST_AT_LEAST_SIZE(xChangeFeedbackControlReq);
        swapl(&stuff->mask);
        return (ProcXChangeFeedbackControl(client));
    }
    
    /******************************************************************************
     *
     * This procedure changes KbdFeedbackClass data.
     *
     */
    
    static int
    ChangeKbdFeedback(ClientPtr client, DeviceIntPtr dev, long unsigned int mask,
                      KbdFeedbackPtr k, xKbdFeedbackCtl * f)
    {
        KeybdCtrl kctrl;
        int t;
        int key = DO_ALL;
    
        if (client->swapped) {
            swaps(&f->length);
            swaps(&f->pitch);
            swaps(&f->duration);
            swapl(&f->led_mask);
            swapl(&f->led_values);
        }
    
        kctrl = k->ctrl;
        if (mask & DvKeyClickPercent) {
            t = f->click;
            if (t == -1)
                t = defaultKeyboardControl.click;
            else if (t < 0 || t > 100) {
                client->errorValue = t;
                return BadValue;
            }
            kctrl.click = t;
        }
    
        if (mask & DvPercent) {
            t = f->percent;
            if (t == -1)
                t = defaultKeyboardControl.bell;
            else if (t < 0 || t > 100) {
                client->errorValue = t;
                return BadValue;
            }
            kctrl.bell = t;
        }
    
        if (mask & DvPitch) {
            t = f->pitch;
            if (t == -1)
                t = defaultKeyboardControl.bell_pitch;
            else if (t < 0) {
                client->errorValue = t;
                return BadValue;
            }
            kctrl.bell_pitch = t;
        }
    
        if (mask & DvDuration) {
            t = f->duration;
            if (t == -1)
                t = defaultKeyboardControl.bell_duration;
            else if (t < 0) {
                client->errorValue = t;
                return BadValue;
            }
            kctrl.bell_duration = t;
        }
    
        if (mask & DvLed) {
            kctrl.leds &= ~(f->led_mask);
            kctrl.leds |= (f->led_mask & f->led_values);
        }
    
        if (mask & DvKey) {
            key = (KeyCode) f->key;
            if (key < 8 || key > 255) {
                client->errorValue = key;
                return BadValue;
            }
            if (!(mask & DvAutoRepeatMode))
                return BadMatch;
        }
    
        if (mask & DvAutoRepeatMode) {
            int inx = (key >> 3);
            int kmask = (1 << (key & 7));
    
            t = (CARD8) f->auto_repeat_mode;
            if (t == AutoRepeatModeOff) {
                if (key == DO_ALL)
                    kctrl.autoRepeat = FALSE;
                else
                    kctrl.autoRepeats[inx] &= ~kmask;
            }
            else if (t == AutoRepeatModeOn) {
                if (key == DO_ALL)
                    kctrl.autoRepeat = TRUE;
                else
                    kctrl.autoRepeats[inx] |= kmask;
            }
            else if (t == AutoRepeatModeDefault) {
                if (key == DO_ALL)
                    kctrl.autoRepeat = defaultKeyboardControl.autoRepeat;
                else
                    kctrl.autoRepeats[inx] &= ~kmask;
                kctrl.autoRepeats[inx] =
                    (kctrl.autoRepeats[inx] & ~kmask) |
                    (defaultKeyboardControl.autoRepeats[inx] & kmask);
            }
            else {
                client->errorValue = t;
                return BadValue;
            }
        }
    
        k->ctrl = kctrl;
        (*k->CtrlProc) (dev, &k->ctrl);
        return Success;
    }
    
    /******************************************************************************
     *
     * This procedure changes PtrFeedbackClass data.
     *
     */
    
    static int
    ChangePtrFeedback(ClientPtr client, DeviceIntPtr dev, long unsigned int mask,
                      PtrFeedbackPtr p, xPtrFeedbackCtl * f)
    {
        PtrCtrl pctrl;              /* might get BadValue part way through */
    
        if (client->swapped) {
            swaps(&f->length);
            swaps(&f->num);
            swaps(&f->denom);
            swaps(&f->thresh);
        }
    
        pctrl = p->ctrl;
        if (mask & DvAccelNum) {
            int accelNum;
    
            accelNum = f->num;
            if (accelNum == -1)
                pctrl.num = defaultPointerControl.num;
            else if (accelNum < 0) {
                client->errorValue = accelNum;
                return BadValue;
            }
            else
                pctrl.num = accelNum;
        }
    
        if (mask & DvAccelDenom) {
            int accelDenom;
    
            accelDenom = f->denom;
            if (accelDenom == -1)
                pctrl.den = defaultPointerControl.den;
            else if (accelDenom <= 0) {
                client->errorValue = accelDenom;
                return BadValue;
            }
            else
                pctrl.den = accelDenom;
        }
    
        if (mask & DvThreshold) {
            int threshold;
    
            threshold = f->thresh;
            if (threshold == -1)
                pctrl.threshold = defaultPointerControl.threshold;
            else if (threshold < 0) {
                client->errorValue = threshold;
                return BadValue;
            }
            else
                pctrl.threshold = threshold;
        }
    
        p->ctrl = pctrl;
        (*p->CtrlProc) (dev, &p->ctrl);
        return Success;
    }
    
    /******************************************************************************
     *
     * This procedure changes IntegerFeedbackClass data.
     *
     */
    
    static int
    ChangeIntegerFeedback(ClientPtr client, DeviceIntPtr dev,
                          long unsigned int mask, IntegerFeedbackPtr i,
                          xIntegerFeedbackCtl * f)
    {
        if (client->swapped) {
            swaps(&f->length);
            swapl(&f->int_to_display);
        }
    
        i->ctrl.integer_displayed = f->int_to_display;
        (*i->CtrlProc) (dev, &i->ctrl);
        return Success;
    }
    
    /******************************************************************************
     *
     * This procedure changes StringFeedbackClass data.
     *
     */
    
    static int
    ChangeStringFeedback(ClientPtr client, DeviceIntPtr dev,
                         long unsigned int mask, StringFeedbackPtr s,
                         xStringFeedbackCtl * f)
    {
        int i, j;
        KeySym *syms, *sup_syms;
    
        syms = (KeySym *) (f + 1);
        if (client->swapped) {
            swaps(&f->length);      /* swapped num_keysyms in calling proc */
            SwapLongs((CARD32 *) syms, f->num_keysyms);
        }
    
        if (f->num_keysyms > s->ctrl.max_symbols)
            return BadValue;
    
        sup_syms = s->ctrl.symbols_supported;
        for (i = 0; i < f->num_keysyms; i++) {
            for (j = 0; j < s->ctrl.num_symbols_supported; j++)
                if (*(syms + i) == *(sup_syms + j))
                    break;
            if (j == s->ctrl.num_symbols_supported)
                return BadMatch;
        }
    
        s->ctrl.num_symbols_displayed = f->num_keysyms;
        for (i = 0; i < f->num_keysyms; i++)
            *(s->ctrl.symbols_displayed + i) = *(syms + i);
        (*s->CtrlProc) (dev, &s->ctrl);
        return Success;
    }
    
    /******************************************************************************
     *
     * This procedure changes BellFeedbackClass data.
     *
     */
    
    static int
    ChangeBellFeedback(ClientPtr client, DeviceIntPtr dev,
                       long unsigned int mask, BellFeedbackPtr b,
                       xBellFeedbackCtl * f)
    {
        int t;
        BellCtrl bctrl;             /* might get BadValue part way through */
    
        if (client->swapped) {
            swaps(&f->length);
            swaps(&f->pitch);
            swaps(&f->duration);
        }
    
        bctrl = b->ctrl;
        if (mask & DvPercent) {
            t = f->percent;
            if (t == -1)
                t = defaultKeyboardControl.bell;
            else if (t < 0 || t > 100) {
                client->errorValue = t;
                return BadValue;
            }
            bctrl.percent = t;
        }
    
        if (mask & DvPitch) {
            t = f->pitch;
            if (t == -1)
                t = defaultKeyboardControl.bell_pitch;
            else if (t < 0) {
                client->errorValue = t;
                return BadValue;
            }
            bctrl.pitch = t;
        }
    
        if (mask & DvDuration) {
            t = f->duration;
            if (t == -1)
                t = defaultKeyboardControl.bell_duration;
            else if (t < 0) {
                client->errorValue = t;
                return BadValue;
            }
            bctrl.duration = t;
        }
        b->ctrl = bctrl;
        (*b->CtrlProc) (dev, &b->ctrl);
        return Success;
    }
    
    /******************************************************************************
     *
     * This procedure changes LedFeedbackClass data.
     *
     */
    
    static int
    ChangeLedFeedback(ClientPtr client, DeviceIntPtr dev, long unsigned int mask,
                      LedFeedbackPtr l, xLedFeedbackCtl * f)
    {
        LedCtrl lctrl;              /* might get BadValue part way through */
    
        if (client->swapped) {
            swaps(&f->length);
            swapl(&f->led_values);
            swapl(&f->led_mask);
        }
    
        f->led_mask &= l->ctrl.led_mask;    /* set only supported leds */
        f->led_values &= l->ctrl.led_mask;  /* set only supported leds */
        if (mask & DvLed) {
            lctrl.led_mask = f->led_mask;
            lctrl.led_values = f->led_values;
            (*l->CtrlProc) (dev, &lctrl);
            l->ctrl.led_values &= ~(f->led_mask);   /* zero changed leds */
            l->ctrl.led_values |= (f->led_mask & f->led_values);    /* OR in set leds */
        }
    
        return Success;
    }
    
    /***********************************************************************
     *
     * Change the control attributes.
     *
     */
    
    int
    ProcXChangeFeedbackControl(ClientPtr client)
    {
        unsigned len;
        DeviceIntPtr dev;
        KbdFeedbackPtr k;
        PtrFeedbackPtr p;
        IntegerFeedbackPtr i;
        StringFeedbackPtr s;
        BellFeedbackPtr b;
        LedFeedbackPtr l;
        int rc;
    
        REQUEST(xChangeFeedbackControlReq);
        REQUEST_AT_LEAST_SIZE(xChangeFeedbackControlReq);
    
        len = stuff->length - bytes_to_int32(sizeof(xChangeFeedbackControlReq));
        rc = dixLookupDevice(&dev, stuff->deviceid, client, DixManageAccess);
        if (rc != Success)
            return rc;
    
        switch (stuff->feedbackid) {
        case KbdFeedbackClass:
            if (len != bytes_to_int32(sizeof(xKbdFeedbackCtl)))
                return BadLength;
    
            for (k = dev->kbdfeed; k; k = k->next)
                if (k->ctrl.id == ((xKbdFeedbackCtl *) &stuff[1])->id)
                    return ChangeKbdFeedback(client, dev, stuff->mask, k,
                                             (xKbdFeedbackCtl *) &stuff[1]);
            break;
        case PtrFeedbackClass:
            if (len != bytes_to_int32(sizeof(xPtrFeedbackCtl)))
                return BadLength;
    
            for (p = dev->ptrfeed; p; p = p->next)
                if (p->ctrl.id == ((xPtrFeedbackCtl *) &stuff[1])->id)
                    return ChangePtrFeedback(client, dev, stuff->mask, p,
                                             (xPtrFeedbackCtl *) &stuff[1]);
            break;
        case StringFeedbackClass:
        {
            xStringFeedbackCtl *f;
    
            REQUEST_AT_LEAST_EXTRA_SIZE(xChangeFeedbackControlReq,
                                        sizeof(xStringFeedbackCtl));
            f = ((xStringFeedbackCtl *) &stuff[1]);
            if (client->swapped) {
                if (len < bytes_to_int32(sizeof(xStringFeedbackCtl)))
                    return BadLength;
                swaps(&f->num_keysyms);
            }
            if (len !=
                (bytes_to_int32(sizeof(xStringFeedbackCtl)) + f->num_keysyms))
                return BadLength;
    
            for (s = dev->stringfeed; s; s = s->next)
                if (s->ctrl.id == ((xStringFeedbackCtl *) &stuff[1])->id)
                    return ChangeStringFeedback(client, dev, stuff->mask, s,
                                                (xStringFeedbackCtl *) &stuff[1]);
            break;
        }
        case IntegerFeedbackClass:
            if (len != bytes_to_int32(sizeof(xIntegerFeedbackCtl)))
                return BadLength;
    
            for (i = dev->intfeed; i; i = i->next)
                if (i->ctrl.id == ((xIntegerFeedbackCtl *) &stuff[1])->id)
                    return ChangeIntegerFeedback(client, dev, stuff->mask, i,
                                                 (xIntegerFeedbackCtl *) &
                                                 stuff[1]);
            break;
        case LedFeedbackClass:
            if (len != bytes_to_int32(sizeof(xLedFeedbackCtl)))
                return BadLength;
    
            for (l = dev->leds; l; l = l->next)
                if (l->ctrl.id == ((xLedFeedbackCtl *) &stuff[1])->id)
                    return ChangeLedFeedback(client, dev, stuff->mask, l,
                                             (xLedFeedbackCtl *) &stuff[1]);
            break;
        case BellFeedbackClass:
            if (len != bytes_to_int32(sizeof(xBellFeedbackCtl)))
                return BadLength;
    
            for (b = dev->bell; b; b = b->next)
                if (b->ctrl.id == ((xBellFeedbackCtl *) &stuff[1])->id)
                    return ChangeBellFeedback(client, dev, stuff->mask, b,
                                              (xBellFeedbackCtl *) &stuff[1]);
            break;
        default:
            break;
        }
    
        return BadMatch;
    }