Comment 15 for bug 26650

Message-ID: <email address hidden>
Date: Thu, 8 Dec 2005 14:33:50 +0100
From: Martin Pitt <email address hidden>
To: Frank =?iso-8859-1?Q?K=FCster?= <email address hidden>
Cc: Martin Pitt <email address hidden>, <email address hidden>
Subject: Re: Bug#342292: Fwd: Re: [vendor-sec] xpdf update - patch wrong?

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Hi Frank!

Frank K=FCster [2005-12-08 13:17 +0100]:
> Martin Pitt <email address hidden> wrote:
>=20
> > Hi!
> >
> > I'm currently preparing Ubuntu security updates for these issues, and
> > I noticed that the upstream provided patch is wrong. I sent the mail
> > below to upstream (and some others).
> >
> > Can you please check that you indeed fixed (tetex-bin)/will fix
> > (poppler) DCTStream::readProgressiveSOF(), too?
> [...]
> > It seems that the patch linked from these advisories [1] is a little
> > bit flawed: it checks numComps twice in DCTStream::readBaselineSOF(),
> > but does not check it in DCTStream::readProgressiveSOF().
>=20
> We have the same flaw in our upload. Would you be so kind and check the
> updated patch at=20
>=20
> http://svn.debian.org/wsvn/pkg-tetex/tetex-bin/trunk/debian/patches/patch=
-CVE-2005-3191+2+3?op=3Dfile&rev=3D0&sc=3D0

The DCTStream::readProgressiveSOF() seems to be correct now, however,
there is still a flaw in=20

- img.tiles =3D (JPXTile *)gmalloc(img.nXTiles * img.nYTiles *
- sizeof(JPXTile));
+ nTiles =3D img.nXTiles * img.nYTiles;
+ // check for overflow before allocating memory
+ if (nTiles =3D=3D 0 || nTiles / img.nXTiles !=3D img.nYTiles) {
+ error(getPos(), "Bad tile count in JPX SIZ marker segment");
+ return gFalse;
+ }
+ img.tiles =3D (JPXTile *)gmalloc(nTiles * sizeof(JPXTile));

gmalloc does a multiplication which is not checked for integer
overflows. xpdf uses gmallocn() which does that check.

I'll send you an updated patch very soon, I just finished patching
tetex-bin 2.0.2, cupsys, xpdf, poppler, etc.

Martin

--=20
Martin Pitt http://www.piware.de
Ubuntu Developer http://www.ubuntu.com
Debian Developer http://www.debian.org

In a world without walls and fences, who needs Windows and Gates?

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