Date: Wed, 26 Oct 2016 06:27:49 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: freebsd-security@freebsd.org Subject: Re: FreeBSD Security Advisory FreeBSD-SA-16:15.sysarch [REVISED] Message-ID: <20161026042748.GG60006@garage.freebsd.pl> In-Reply-To: <20161025173641.BCDFD1911@freefall.freebsd.org> References: <20161025173641.BCDFD1911@freefall.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--orO6xySwJI16pVnm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi guys, since when do we publish security advisories for local DoSes? On Tue, Oct 25, 2016 at 05:36:41PM +0000, FreeBSD Security Advisories wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 >=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D > FreeBSD-SA-16:15.sysarch [REVISED] Security Advi= sory > The FreeBSD Pro= ject >=20 > Topic: Incorrect argument validation in sysarch(2) >=20 > Category: core > Module: kernel > Announced: 2016-10-25 > Credits: Core Security, ahaha from Chaitin Tech > Affects: All supported versions of FreeBSD. > Corrected: 2016-10-25 17:14:50 UTC (stable/11, 11.0-STABLE) > 2016-10-25 17:11:20 UTC (releng/11.0, 11.0-RELEASE-p2) > 2016-10-25 17:16:08 UTC (stable/10, 10.3-STABLE) > 2016-10-25 17:11:15 UTC (releng/10.3, 10.3-RELEASE-p11) > 2016-10-25 17:11:11 UTC (releng/10.2, 10.2-RELEASE-p24) > 2016-10-25 17:11:07 UTC (releng/10.1, 10.1-RELEASE-p41) > 2016-10-25 17:16:58 UTC (stable/9, 9.3-STABLE) > 2016-10-25 17:11:02 UTC (releng/9.3, 9.3-RELEASE-p49) > CVE Name: CVE-2016-1885 >=20 > For general information regarding FreeBSD Security Advisories, > including descriptions of the fields above, security branches, and the > following sections, please visit <URL:https://security.FreeBSD.org/>. >=20 > 0. Revision history >=20 > v1.0 2016-03-16 Initial release. > v1.1 2016-10-25 Revised patch to address a problem pointed out by > ahaha from Chaitin Tech. >=20 > I. Background >=20 > The IA-32 architecture allows programs to define segments, which provides > based and size-limited view into the program address space. The > memory-resident processor structure, called Local Descriptor Table, > usually abbreviated LDT, contains definitions of the segments. Since > incorrect or malicious segments would breach system integrity, operating > systems do not provide processes direct access to the LDT, instead > they provide system calls which allow controlled installation and removal= =20 > of segments. >=20 > II. Problem Description >=20 > A special combination of sysarch(2) arguments, specify a request to > uninstall a set of descriptors from the LDT. The start descriptor > is cleared and the number of descriptors are provided. Due to lack > of sufficient bounds checking during argument validity verification, > unbound zero'ing of the process LDT and adjacent memory can be initiated > from usermode. >=20 > III. Impact >=20 > This vulnerability could cause the kernel to panic. In addition it is > possible to perform a local Denial of Service against the system by > unprivileged processes.=20 >=20 > IV. Workaround >=20 > No workaround is available, but only the amd64 architecture is affected. >=20 > V. Solution >=20 > Perform one of the following: >=20 > 1) Upgrade your vulnerable system to a supported FreeBSD stable or > release / security branch (releng) dated after the correction date. >=20 > Reboot is required. >=20 > 2) To update your vulnerable system via a binary patch: >=20 > Systems running a RELEASE version of FreeBSD platforms can be updated > via the freebsd-update(8) utility: >=20 > # freebsd-update fetch > # freebsd-update install >=20 > Reboot is required. >=20 > 3) To update your vulnerable system via a source code patch: >=20 > The following patches have been verified to apply to the applicable > FreeBSD release branches. >=20 > [*** v1.1 NOTE ***] If your sources are not yet patched using the initial= ly > published advisory patches, then you need to apply both sysarch.patch and > sysarch-01.patch. If your sources are already updated, or patched with > patches from the initial advisory, then you need to apply sysarch-01.patch > only. >=20 > a) Download the relevant patch from the location below, and verify the > detached PGP signature using your PGP utility. >=20 > [ FreeBSD system not patched with original SA-16:15 patch] > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch.patch > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch.patch.asc > # gpg --verify sysarch.patch.asc >=20 > [ FreeBSD system that has been patched with original SA-16:15 patch] > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch-01.patch > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch-01.patch.asc > # gpg --verify sysarch-01.patch.asc >=20 > b) Apply the patch(es). Execute the following commands as root for > every patch file downloaded: >=20 > # cd /usr/src > # patch < /path/to/patch >=20 > c) Recompile your kernel as described in > <URL:https://www.FreeBSD.org/handbook/kernelconfig.html>; and reboot the > system. >=20 > VI. Correction details >=20 > The following list contains the correction revision numbers for each > affected branch. >=20 > Branch/path Revision > - -----------------------------------------------------------------------= -- > stable/9/ r307941 > releng/9.3/ r307931 > stable/10/ r307940 > releng/10.1/ r307932 > releng/10.2/ r307933 > releng/10.3/ r307934 > stable/11/ r307938 > releng/11.0/ r307935 > - -----------------------------------------------------------------------= -- >=20 > To see which files were modified by a particular revision, run the > following command, replacing NNNNNN with the revision number, on a > machine with Subversion installed: >=20 > # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base >=20 > Or visit the following URL, replacing NNNNNN with the revision number: >=20 > <URL:https://svnweb.freebsd.org/base?view=3Drevision&revision=3DNNNNNN>; >=20 > VII. References >=20 > <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2016-1885>; >=20 > The latest revision of this advisory is available at > <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:15.sysarch.asc>; > -----BEGIN PGP SIGNATURE----- >=20 > iQIcBAEBCgAGBQJYD5VZAAoJEO1n7NZdz2rnYT4QAMmnfUBnxiNHfzaEDMe2oU+H > WIVFzFtU5FTAm3wJ3JORU1euqhusDoB7D8nova30alM2bHHd86epBGgym1Q+hxR2 > qTI+d8QimvQUWelz7DWPh0h3ZNlVfDxY8vKlr5SS0W/HOMjbG/O6U1AIw5p7cPaa > LkDpqo2IN8xBL6tJFUKNEQS/GzuU2HtfKhQK0/ojT4DW61AkOZn4SZzzYBz3iO4p > a8Otv4+aHzyNjTZRm/33SrFzdG0RZWyT/WXsEHlv5NiXVMPML+oY918jppqClkoO > pwjcneWTqgYrE4vvVOADKOlWyNa4jFmPQSW7MmNEaF4RMd8TMcE/cBTKOi41YuOp > la1JzvtWUnou7oQqy/xKr0S/Wa2x6ZhR4vBg28fkfrQhn55N+qqDicQ3F907dOm5 > A0ERHKgImlWSGM+Sf2CJyrUJUNUye0bVQMhrM4e3psZ7Jr20IXjnhppr1mufCjTH > H+aEHv43o/1HuoltnjstiBZ/CZpFdIXkBpsHtzteZR2y+pmZFA9bB4uZeeML0mj3 > /cxj8rgPRmcjk6nSsnLWhq2YEFAZBC/lv43wqSrXE9+BBpSh6zM5NCTPb50/dBqf > V553uuGEvJlHmOAoveXxYyxKcGpgZAcgJjWpAkCpoVxgdrbtLcPY5Z+8cy8fMO3G > YHOkZydbLPaXOXimZfut > =3DNWuL > -----END PGP SIGNATURE----- > _______________________________________________ > freebsd-security-notifications@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications > To unsubscribe, send any mail to "freebsd-security-notifications-unsubscr= ibe@freebsd.org" --=20 Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://mobter.com --orO6xySwJI16pVnm Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCgAGBQJYEDDEAAoJEJVLhSuxKFt180kQAMv8ah16hXs8DTmZVoSaYBaP rSrIeCgieUcdYYuj5j/fCU3KYbChOF5o5lvaYRwxByDqmdst/xJjMUtRug1SQlsP y9IJ55jD4dH9zisWWRbOM+WWgb2dL9M7d5QO3ZyRhe5FbeHp7mViJsgveDd0ZFPy iG3sl/UXe3Vp16CSkLKBPO0HHcPy9Hz1P2jwsT5yaD1cYgofy41wyIe2U9PYlkB2 qz46DzERqft04P745KGWbj5A8vi38nnYyDmicSaf7ILv39dXlGTE54MW09bj1/sM fI076sm22/P30u1NEzWjh2vIzRFsaKByAH+lG/cjn0H3wleCrVF+d5Zl0j0V3Ysc F0QLwtJDJF/xuESKROqNVzhNdNweulRw9XJmgcz0WjqBqztJB67YauHZtyDxbgLh jCt8Nee8ieEporWYQcHRPKRv5OoFtsGNZnd78SMcxBFOSSR10xgiKqvEadZWo5S0 wkTHE974KTprD8PhYZVe3Wy6ZHVO0LhWIh2lOLxKbQoLAooOBENpNeblQloaKTFJ RIPrDRAjD3rL7IeVlEUG65eOe07DMPVmhestsUmYxKtqeOoR1PionH1PB1UqW8w3 zPP6wgy1NwJA1mExtvhdxHneRYzsoqma3yhYqtcGS9PZihEtnhdssAr1C5DQl2xj hI+G0I+NhRlawKXL8GDm =IQv9 -----END PGP SIGNATURE----- --orO6xySwJI16pVnm--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20161026042748.GG60006>