-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-EN-21:19.libcasper Errata Notice The FreeBSD Project Topic: libcasper assertion failure Category: core Module: libcasper Announced: 2021-06-29 Credits: Borja Marcos, Jung-uk Kim Affects: All supported versions of FreeBSD. Corrected: 2021-06-15 18:14:43 UTC (stable/13, 13.0-STABLE) 2021-06-29 17:09:02 UTC (releng/13.0, 13.0-RELEASE-p3) 2021-06-16 20:25:22 UTC (stable/12, 12.2-STABLE) 2021-06-29 20:26:12 UTC (releng/12.2, 12.2-RELEASE-p9) 2021-06-16 20:30:46 UTC (stable/11, 11.4-STABLE) 2021-06-29 20:25:32 UTC (releng/11.4, 11.4-RELEASE-p12) For general information regarding FreeBSD Errata Notices and Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background libcasper(3) allows Capsicum-sandboxed applications to define and use system interfaces which are ordinarily disallowed. It is used by multiple programs in the base system, such as logger(1). II. Problem Description libcasper(3) creates service processes by forking the calling process, so they initially inherit the calling process' file descriptor table. Casper services expect the lowest 3 file descriptors, traditionally corresponding to standard input, output, and error, are redirected to /dev/null. libcasper(3) ensures this is the case. However, it did not handle the possibility that one of them is closed, and this scenario would trigger an assertion failure during service creation, resulting in a crash. III. Impact Some applications, such as logger(1), may crash if one of the standard descriptors is closed when Casper services are started, typically during program initialization. IV. Workaround No workaround is available. V. Solution Upgrade your system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Perform one of the following: 1) To update your system via a binary patch: Systems running a RELEASE version of FreeBSD on the amd64, i386, or (on FreeBSD 13 and later) arm64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install 2) 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 13.0] # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.13.patch # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.13.patch.asc # gpg --verify libcasper.13.patch.asc [FreeBSD 12.2] # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.12.patch # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.12.patch.asc # gpg --verify libcasper.12.patch.asc [FreeBSD 11.4] # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.11.patch # fetch https://security.FreeBSD.org/patches/EN-21:19/libcasper.11.patch.asc # gpg --verify libcasper.11.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 . Restart all daemons that use the library, or reboot the system. VI. Correction details This issue is corrected by the corresponding Git commit hash or Subversion revision number in the following stable and release branches: Branch/path Hash Revision - ------------------------------------------------------------------------- stable/13/ 934e10b4a388 stable/13-n246041 releng/13.0/ ba5ed8109cc9 releng/13.0-n244748 stable/12/ r369994 releng/12.2/ r370063 stable/11/ r370004 releng/11.4/ r370059 - ------------------------------------------------------------------------- For FreeBSD 13 and later: Run the following command to see which files were modified by a particular commit: # git show --stat Or visit the following URL, replacing NNNNNN with the hash: To determine the commit count in a working tree (for comparison against nNNNNNN in the table above), run: # git rev-list --count --first-parent HEAD For FreeBSD 12 and earlier: Run the following command to see which files were modified by a particular revision, replacing NNNNNN with the revision number: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAmDcD0QACgkQ05eS9J6n 5cJ3oRAAhTR7w6yCDjLSExq+/mizNNPy/EHyTxnoexUV6vGnPL3wEno6IVhqTPS3 Vuq9m7noXOgwHGO0Mbbuc9vkZJWjfoXoeEqylfkSxH3mDb+hkBKPGyZNZWup6XCd ykm2FB+c65t/neF9n/6OesT7mIUp+k4UIwTOXuO5rRolWkGrSawHLYWucww3LAF1 p2bD7Gdc8m/Ymj5FDJBPMWAtFW7QNmocyQI4vGAgqoW2DXokoy/BVTYE6pU3RQ3G ZTkXMa5Vb6LlbnP3ho14Jap/6gXcUAnB96bXuWG3JIsNvslZzSLe1jRKD0QXNJvw PFRLe8LBOA/VZ02xyoHdlAkAnTMk+vv7LU6K6Z7UIr8YzwkS0UYvvVvEr03E1Psm qvzhs+qml2ATn4/C4sjzUEAq5YRqBPQOSmKFmGDAOzy179L1YM8IFIdm11hpGlu5 8T+n/egH5IVQ7U35MiXUkomvO7F2PWBP7oGI0GDIvKa7UuR+gsMwkVyE68W2442i 3JaBCqntchJjS2P+ixnXR2qCI81zCRlG+/m/1gBgztA8+K85l0P0gt8VAhcakbES WXh4rX6BSvMqDI1Ex3wS00zjZOSM/HoNz+HGmpUiQ7RYVinrt4Av3vdbv2hLm96l Iu28g8UCf4HNUAVAbgtiHmU74TBKGSyDPVcQVvegMG/YEhof9Fw= =LQ0r -----END PGP SIGNATURE-----