FreeBSD Errata Notice FreeBSD-EN-21:25.bhyve
24 August, 2021 by email@example.com | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-EN-21:25.bhyve Errata Notice The FreeBSD Project Topic: Fix NVMe iovec construction for large IOs Category: core Module: bhyve Announced: 2021-08-24 Affects: FreeBSD 12.2 and later. Corrected: 2021-07-09 14:24:14 UTC (stable/13, 13.0-STABLE) 2021-08-24 17:25:47 UTC (releng/13.0, 13.0-RELEASE-p4) 2021-07-09 14:25:45 UTC (stable/12, 12.2-STABLE) 2021-08-24 18:32:11 UTC (releng/12.2, 12.2-RELEASE-p10) 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 bhyve(8) is a hypervisor that supports running a variety of guest operating systems in virtual machines. Newer UEFI code in Red Hat Enterprise Linux (RHEL) 8.4 and later (as well as applicable variants) will not boot in newly installed guests. II. Problem Description By default, NVMe data transfer operations use a scatter-gather list in which all entries point to a fixed-size memory region. For example, if the memory page size is 4KB, a 2MB IO requires 512 entries. Lists themselves are also fixed in size (default is 512 entries). Because the list size is fixed, the last entry is special. If the IO requires more than 512 entries, the last entry in the list contains the address of the next list of entries. But if the IO requires exactly 512 entries, the last entry points to data. The NVMe emulation missed this logic and unconditionally treated the last entry as a pointer to the next list. III. Impact When a RHEL 8.4 and later (or variants) are installed as guests within bhyve(8) on emulated NVMe storage, the system will not boot due to a newer UEFI driver that is included with these distributions. IV. Workaround Installation of a RHEL 8.3 guest and performing an in-place upgrade. 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. # fetch https://security.FreeBSD.org/patches/EN-21:25/bhyve.patch # fetch https://security.FreeBSD.org/patches/EN-21:25/bhyve.patch.asc # gpg --verify bhyve.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>. 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/ a7761d19dacd stable/13-n246220 releng/13.0/ 4f590ee3ed7e releng/13.0-n244755 stable/12/ r370107 releng/12.2/ r370392 - ------------------------------------------------------------------------- For FreeBSD 13 and later: Run the following command to see which files were modified by a particular commit: # git show --stat <commit hash> Or visit the following URL, replacing NNNNNN with the hash: <URL:https://cgit.freebsd.org/src/commit/?id=NNNNNN> 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: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:https://bugs.freebsd.org/bugzilla/show_bug.cgi?id%6422> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-EN-21:25.bhyve.asc> -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAmElV10ACgkQ05eS9J6n 5cJQ6A//ad84xTf/SfMMEqlFaQbNtuh4egvTgWRIt8JkkzpTyO+VRMhJ9pJIW0LP G23xBQYOkUjjb8WvZpQ0iP4PsMHaKzzwiVO2qUZ10IgIJbxjyIbSo/LJxFSUl50K zwuxtM2LKIc6VDasMsg5B3FkCojlZEckN4HykzK1HHV9PvwCOGMQXdFDklmdKdwx kGr4tk5r3yG3sgfY98+TdT34Y1jioWzT6LFscXfEWhQQXFa02m+AKPFsXOl+eSVt O3mgaazyTT4LWiT9ZEj9dN6yJ3aseG4bpq/FIO4bXBOU35ttdsMxtn87muDvXRE3 rYHALHYhsgpNlP1Pa0FD0/syZ8VVV+L5hQ9+n7oPlHOmMVxoDIC/TireyCNtHM0C yEPWu3rWRBsK0YTuP57ezSRnnaAXqInSmLX1IkmzBSwAoySEED8ONlypPB4qh19M oUcOE661JAWA84ZP02gZsjjRaZOihv0BVmC0RXkCSe3VGAMuxCKYSLcupwFn34pA gEe+IL6WpR2fCiR3ncLjvhZrGlBfGDEfGmTRD5ceVMLaZKly8D9IpCuXK62Gi1DA pjAHJ9T6BmWW5Cxx5eJJESuhRldREf6KAVifB8K/DtWtp2BquILWj9pd4vuUYhz9 eYva+/shAJE5PGKva9k0Erk++bE3Cephnjh9SgnWlZnoeSLcJ3k=1wKt -----END PGP SIGNATURE----- _______________________________________________ firstname.lastname@example.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "email@example.com"