Date: Tue, 27 Nov 2018 21:22:31 +0000 (UTC) From: FreeBSD Errata Notices <errata-notices@freebsd.org> To: FreeBSD Errata Notices <errata-notices@freebsd.org> Subject: [FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-18:15.loader Message-ID: <20181127212231.CC3A01A827@freefall.freebsd.org>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-EN-18:15.loader Errata Notice The FreeBSD Project Topic: Deferred kernel loading breaks loader password Category: core Module: loader Announced: 2018-11-27 Credits: Devin Teske Affects: All supported versions of FreeBSD. Corrected: 2018-10-24 23:17:17 UTC (stable/11, 11.2-STABLE) 2018-11-27 19:45:25 UTC (releng/11.2, 11.2-RELEASE-p5) For general information regarding FreeBSD Errata Notices and Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:https://security.FreeBSD.org/>. I. Background The loader is a FreeBSD component which is part of the boot sequence for a machine. The loader is most commonly visible with the "beastie" boot menu, allowing specification of different boot time parameters. II. Problem Description A change in the loader to allow deferred loading of the kernel introduced a bug when using a loader password. After this change and when the loader password is enabled, the menu is not loaded and instead the machine goes into the autoboot routine. The autoboot routine then fails when the kernel has not yet been loaded, yielding a loader prompt where the user has full control of the boot process. III. Impact Setting the loader password with the intention of preventing the user from bypassing the boot process instead causes the boot to fail and gives the user full control of the boot process. IV. Workaround No workaround is available, but systems that do not use a loader password are not vulnerable. V. Solution Perform one of the following: 1) Upgrade your system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Afterward, reboot the system. 2) To update your system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install Afterward, reboot the system. 3) To update your system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 11.2] # fetch https://security.FreeBSD.org/patches/EN-18:15/loader.patch # fetch https://security.FreeBSD.org/patches/EN-18:15/loader.patch.asc # gpg --verify loader.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html> and reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/11/ r339697 releng/11.2/ r341093 - ------------------------------------------------------------------------- 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: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-EN-18:15.loader.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAlv9n+tfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cJRKQ//cJzGNBcKnH3cAltXRM2eWqv6L2UAPYfOs5QEArIB5x4IR+wqc53AbyG4 AlpWAUf1KCwOFV+ceflihmYiWPPUqSV6nn+0My+uEFQebu8j00D5Mer/x9g6SikB x65zXS//rHidaf5KWOKMajEW+jtC9JS42ffdyk+KgEYM4UCNY60iKhJ74rtwRjun RwYKBXdtOcbS9Tp/SIIB3tQm1orhK5xe4w+kG4nM9Cz5OYk4j/GmcudWICjzjNzG QxGENiDePEjLoCZTHn2Rgntwp0AjNY5FxdR8CgN5GtYHIepJIscE7BlYA6kZDoG9 e+01e3d7oAz92Dx8h59AkOGZPNI2lL4ZnBAcrpsZa+YkV67kxMHOIGp6faRYdWsf +Ew8fh7AbVVhBO4yKWyoHkbREof07Iq3hXX7pi/Imb+nsYYPC6x0vax+qv823P4/ jnqIryC3MWezOIkTD6B752yED3prP3TDFi+/Lo2ke2K4rPkVRsMfRojcKaKVnWLl HpgyffSiVv/dwv005Mdx0kCBnKtZthO9D0GHZSkRIXw2r5C5QQ8F7/EABfWFq1iN sM+J682zjJhbFgFzJGceAQGrgVlN91AIl3Ipp2ggi33qQTEOreItRJdN7WBgSI3s fTqA6OqgbknpWmCvusu/gi+SMjbO3Hk2hR6noB4bDVNPhPPCIZE= =om/y -----END PGP SIGNATURE-----
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