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| author | Alan Coopersmith <alan.coopersmith@oracle.com> | 2013-03-01 22:49:01 -0800 |
|---|---|---|
| committer | Ulrich Sibiller <uli42@gmx.de> | 2016-10-12 09:34:38 +0200 |
| commit | 7d18bbe93809a209dcd3590c4f519f19251323d9 (patch) | |
| tree | 5071171da34c7444246890ffa88b8686d2a0cfab /nx-X11 | |
| parent | 29779559c92c3058edc298ca0a6e59e1293262b6 (diff) | |
| download | nx-libs-7d18bbe93809a209dcd3590c4f519f19251323d9.tar.gz nx-libs-7d18bbe93809a209dcd3590c4f519f19251323d9.tar.bz2 nx-libs-7d18bbe93809a209dcd3590c4f519f19251323d9.zip | |
integer overflow in XGetMotionEvents() [CVE-2013-1981 4/13]
If the reported number of motion events is too large, the calculations
to allocate memory for them may overflow, leaving us writing beyond the
bounds of the allocation.
v2: Ensure nEvents is set to 0 when returning NULL events pointer
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Signed-off-by: Julien Cristau <jcristau@debian.org>
Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>
Diffstat (limited to 'nx-X11')
| -rw-r--r-- | nx-X11/lib/X11/GetMoEv.c | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/nx-X11/lib/X11/GetMoEv.c b/nx-X11/lib/X11/GetMoEv.c index 3db176feb..ad9c77277 100644 --- a/nx-X11/lib/X11/GetMoEv.c +++ b/nx-X11/lib/X11/GetMoEv.c @@ -28,6 +28,7 @@ in this Software without prior written authorization from The Open Group. #include <config.h> #endif #include "Xlibint.h" +#include <limits.h> XTimeCoord *XGetMotionEvents( register Display *dpy, @@ -39,7 +40,6 @@ XTimeCoord *XGetMotionEvents( xGetMotionEventsReply rep; register xGetMotionEventsReq *req; XTimeCoord *tc = NULL; - long nbytes; LockDisplay(dpy); GetReq(GetMotionEvents, req); req->window = w; @@ -52,26 +52,22 @@ XTimeCoord *XGetMotionEvents( return (NULL); } - if (rep.nEvents) { - if (! (tc = (XTimeCoord *) - Xmalloc( (unsigned) - (nbytes = (long) rep.nEvents * sizeof(XTimeCoord))))) { - _XEatData (dpy, (unsigned long) nbytes); - UnlockDisplay(dpy); - SyncHandle(); - return (NULL); - } + if (rep.nEvents && (rep.nEvents < (INT_MAX / sizeof(XTimeCoord)))) + tc = Xmalloc(rep.nEvents * sizeof(XTimeCoord)); + if (tc == NULL) { + /* server returned either no events or a bad event count */ + *nEvents = 0; + _XEatDataWords (dpy, rep.length); } - - *nEvents = rep.nEvents; - nbytes = SIZEOF (xTimecoord); + else { register XTimeCoord *tcptr; - register int i; + unsigned int i; xTimecoord xtc; + *nEvents = (int) rep.nEvents; for (i = rep.nEvents, tcptr = tc; i > 0; i--, tcptr++) { - _XRead (dpy, (char *) &xtc, nbytes); + _XRead (dpy, (char *) &xtc, SIZEOF (xTimecoord)); tcptr->time = xtc.time; tcptr->x = cvtINT16toShort (xtc.x); tcptr->y = cvtINT16toShort (xtc.y); |