This is an automated email from the git hooks/post-receive script. x2go pushed a commit to branch 3.6.x in repository nx-libs. commit ac9fbaabd6bdbca6dd1d94fa385aea41fdebf2c1 Author: Karl Tomlinson <xmail@karlt.net> Date: Wed Apr 15 10:16:18 2015 +0200 MakeBigReq: don't move the last word, already handled by Data32 (X.Org CVE-2013-7439). MakeBigReq inserts a length field after the first 4 bytes of the request (after req->length), pushing everything else back by 4 bytes. The current memmove moves everything but the first 4 bytes back. If a request aligns to the end of the buffer pointer when MakeBigReq is invoked for that request, this runs over the buffer. Instead, we need to memmove minus the first 4 bytes (which aren't moved), minus the last 4 bytes (so we still align to the previous tail). The 4 bytes that fell out are already handled with Data32, which will handle the buffermax correctly. The case where req->length = 1 was already not functional. Reported by Abhishek Arya <inferno@chromium.org> (against X.Org BTS). https://bugzilla.mozilla.org/show_bug.cgi?id=803762 Reviewed-by: Jeff Muizelaar <jmuizelaar@mozilla.com> Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net> Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> Rebased-for-NX: Mike Gabriel <mike.gabriel@das-netzwerkteam.de> --- nx-X11/lib/X11/Xlibint.h | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/nx-X11/lib/X11/Xlibint.h b/nx-X11/lib/X11/Xlibint.h index b9a39b2..bcd42b5 100644 --- a/nx-X11/lib/X11/Xlibint.h +++ b/nx-X11/lib/X11/Xlibint.h @@ -528,6 +528,14 @@ extern LockInfoPtr _Xglobal_lock; dpy->request++ #endif +/* + * MakeBigReq sets the CARD16 "req->length" to 0 and inserts a new CARD32 + * length, after req->length, before the data in the request. The new length + * includes the "n" extra 32-bit words. + * + * Do not use MakeBigReq if there is no data already in the request. + * req->length must already be >= 2. + */ #ifdef LONG64 #define MakeBigReq(req,n) \ { \ @@ -535,7 +543,7 @@ extern LockInfoPtr _Xglobal_lock; CARD32 _BRlen = req->length - 1; \ req->length = 0; \ _BRdat = ((CARD32 *)req)[_BRlen]; \ - memmove(((char *)req) + 8, ((char *)req) + 4, _BRlen << 2); \ + memmove(((char *)req) + 8, ((char *)req) + 4, (_BRlen - 1) << 2); \ ((CARD32 *)req)[1] = _BRlen + n + 2; \ Data32(dpy, &_BRdat, 4); \ } @@ -546,12 +554,19 @@ extern LockInfoPtr _Xglobal_lock; CARD32 _BRlen = req->length - 1; \ req->length = 0; \ _BRdat = ((CARD32 *)req)[_BRlen]; \ - memmove(((char *)req) + 8, ((char *)req) + 4, _BRlen << 2); \ + memmove(((char *)req) + 8, ((char *)req) + 4, (_BRlen - 1) << 2); \ ((CARD32 *)req)[1] = _BRlen + n + 2; \ Data32(dpy, &_BRdat, 4); \ } #endif +/* + * SetReqLen increases the count of 32-bit words in the request by "n", + * or by "badlen" if "n" is too large. + * + * Do not use SetReqLen if "req" does not already have data after the + * xReq header. req->length must already be >= 2. + */ #define SetReqLen(req,n,badlen) \ if ((req->length + n) > (unsigned)65535) { \ if (dpy->bigreq_size) { \ -- Alioth's /srv/git/code.x2go.org/nx-libs.git//..//_hooks_/post-receive-email on /srv/git/code.x2go.org/nx-libs.git