FreeBSD Errata Notice FreeBSD-EN-21:13.mpt
27 May, 2021 by errata-notices@freebsd.org | freebsd
FreeBSD-EN-21:13.mpt Errata Notice The FreeBSD Project Topic: mpt(4) I/O errors with a large maxphys value Category: core Module: mpt Announced: 2021-05-26 Affects: FreeBSD 13.0 Corrected: 2021-04-24 00:43:14 UTC (stable/13, 13.0-STABLE) 2021-05-26 19:29:54 UTC (releng/13.0, 13.0-RELEASE-p1) 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 mpt(4) is a driver for LSI disk controllers. II. Problem Description The mpt(4) driver did not correctly handle I/O requests larger than or equal to 2MB and would incorrectly report errors. The I/O request size is limited by the value of the kern.maxphys tunable and the default value is below this threshold. III. Impact With kern.maxphys set to 2MB or larger, I/O to mpt(4) devices will not work correctly. IV. Workaround To work around the problem, ensure that the kern.maxphys value is kept at its default value. V. Solution Upgrade your system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date and reboot. 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 # shutdown -r +10min "Rebooting for an erratum update" 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-21:13/mpt.patch # fetch https://security.FreeBSD.org/patches/EN-21:13/mpt.patch.asc # gpg --verify mpt.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile your kernel as described in <URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and 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/ f0077b4c1dcf stable/13-n245384 releng/13.0/ a8a91efa74e0 releng/13.0-n244734 - ------------------------------------------------------------------------- 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 VII. References The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-EN-21:13.mpt.asc>