Headline
CVE-2019-15880
In FreeBSD 12.1-STABLE before r356911, and 12.1-RELEASE before p5, insufficient checking in the cryptodev module allocated the size of a kernel buffer based on a user-supplied length allowing an unprivileged process to trigger a kernel panic.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:16.cryptodev Security Advisory The FreeBSD Project Topic: Insufficient cryptodev MAC key length check Category: core Module: cryptodev Announced: 2020-05-12 Credits: Yuval Kanarenstein Affects: FreeBSD 12.1 Corrected: 2020-01-20 11:54:00 UTC (stable/12, 12.1-STABLE) 2020-05-12 16:59:09 UTC (releng/12.1, 12.1-RELEASE-p5) CVE Name: CVE-2019-15880 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background The cryptodev module permits userland applications to offload cryptographic requests to device drivers in the kernel. Applications create sessions via file descriptors opened from /dev/crypto. II. Problem Description Requests to create cryptography sessions using a MAC did not validate the user-supplied MAC key length. The cryptodev module allocates a buffer whose size is this user-suppled length. III. Impact An unprivileged process can trigger a kernel panic. IV. Workaround Unload the cryptodev kernel module if it is loaded: # kldunload cryptodev Note that the cryptodev module is not loaded by default and is not used by most applications. Specificially, use of accelerated software cryptography (e.g. AES-NI) in userland applications via libraries such as OpenSSL does not make use of the cryptodev module. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date, and reboot the system. Perform one of the following: 1) To update your vulnerable 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 # shutdown -r +10min “Rebooting for a security update” 2) To update your vulnerable 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/SA-20:16/cryptodev.patch # fetch https://security.FreeBSD.org/patches/SA-20:16/cryptodev.patch.asc # gpg --verify cryptodev.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 and reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/12/ r356911 releng/12.1/ r360977 - ------------------------------------------------------------------------- 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: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl663tdfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cKFbg/+Ou239S9yDp+FTyDlqq4w8p08kh8nHqB6FO6Q6aIxkEgSu/yO9IZsKSnM o05O8iOVOTRR5xSIBN/aW5d4adH81AV6X66NKUZ0bJwAp16v7YIyivY3ySLOB093 oOTy/wlv0jxAYVzOlqMTuVm4dr9dh+9I9kwF94SDY7/maY0pCuUmVCRi2Y5gvCqu LYkDdG0Mq0pka1sGY8aFvG63oMyZ98gkbBNk666SzJnBDq/QDSL0FASCgYDjG1fE R/BciJpucIFi3JPZgSaKi4j56HiN/LaX63A1rdjza3aRh/sLMr7+GHFI3sn474tu xrkRjwnxr7/dghjspHAvsv+8U1oRIGVxeyaQB+Hd4WvNcVzp2McNBJ9c/z7Ugt1r affyXl0JBBkdVa45xDf/weGwwxcmCWxXxv7gDPelf07p3MNjl5G3pPUCUoRA3XE5 Am1v5E0Eui5s/H4ncodY/ECIAHuOfenzdcpK5xCQUMHkgikfiLftNfLWSVOrqEJn Wxl8/ttKWLYYwYDSYrN0kNvQWc6LHsuA1I7Zt7wpRW09wB2OlZ7Hn2nZebTrXjKG P/AeGa+JVCJ2HZzj1+8qxcFHgq8IRINICvq743e2vIQak0KsgqmtvnLavAlv/p3d zPxFJOPAw0bhJj14qLT+cXGC9u3/qrZWWR0b4S7qeMlLG3Cw4fk= =j3X1 -----END PGP SIGNATURE-----