FreeBSD Errata Notices
2019-Jan-09 19:40 UTC
[FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-19:05.kqueue
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================FreeBSD-EN-19:05.kqueue Errata Notice The FreeBSD Project Topic: kqueue race condition and kernel panic Category: core Module: kqueue Announced: 2019-01-09 Credits: Mark Johnston Affects: FreeBSD 11.2 Corrected: 2019-11-24 17:11:47 UTC (stable/11, 11.2-STABLE) 2019-01-09 18:57:38 UTC (releng/11.2, 11.2-RELEASE-p8) 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 kevent(2) is a system call which provides a generic method of notifying the caller when a caller-specified event happens or a condition holds. One use for kevent(2) is to wait for a specified timeout to elapse. II. Problem Description The kevent(2) implementation in the kernel contains a race condition which can be triggered when an event is added and fires shortly after. Most event types are not affected, but timer events can trigger the race if the timeout duration is very short. III. Impact The race condition can cause corruption of a queue structure, leading to a kernel panic when it is later accessed. Applications using kevent(2) may trigger the panic if their usage causes the race condition to occur. IV. Workaround No workaround is available. 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, and reboot. 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 # shutdown -r +30 "Rebooting for errata update" 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-19:05/kqueue.patch # fetch https://security.FreeBSD.org/patches/EN-19:05/kqueue.patch.asc # gpg --verify kqueue.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 The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/11/ r340904 releng/11.2/ r342899 - ------------------------------------------------------------------------- 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-19:05.kqueue.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAlw2RdZfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cK0nRAAgPsdkc/TyBTqpvJrvvNaVd0xgNC2lxnYK3HxOPbo5kqj6XHZxb3KvrrN He6TyGvwGCPHNzlFwHILH+FtFkgrvGVBoPu/U0e/NKRrkhyxPHJMz0bZPu7yqQoG GDFRIsw5D3JKZW38yMD9Menh3mag81OVZii1LfzkcDLLKfwX/zcx1vV7MSwMzoNs 5L7Fm8lg0uIxrrlKvvmrPxfWoZENhCr9CAAdg8moL3thl64NaVVmPo7tXDXosNGo EQYT19SY0FBSboUcpVaChgyZaCFzOeCPuXuJPoUYppIWNiv2S8ZTjuq9d1g4R4SD 7GBMozz8EG1rN0pzhx8mVEECZBzdt5rjggiWKjkOVxH/sy5LQjppONK3VVOygoCz dve2wGq6S1ke/b2NDRpAinmIr8I3x3b7JLNkE5OvNJ6bTLk3ZmpIRYQNYT+eu8Fx GNe/oTU9DRbB4yv0kcKsypHqQ0cKdn6+duYzKGZ4+c86B7IHJgsYoG/NTKYfFzQx BHWuI/P/9pakHESNiDidKRz+z5w679+jIfZDcbBIXaw+PCqzg5a1GFN8Bub2mGLw 2wmVQJV1nbdE+6UbWvaV2seV/bo+N/L8k4QS6OPIDUefLPGgCdRFr/MlLoiTaJ43 p+L3iVlVbiOTCfsCGI/QVQq+IOngKzqSUXN3Ys7PXvvAzSyaTFg=fD2U -----END PGP SIGNATURE-----
Cy Schubert
2019-Jan-09 20:02 UTC
[FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-19:05.kqueue
In message <20190109194030.DFE3A8CC7 at freefall.freebsd.org>, FreeBSD Errata Noti ces writes:> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > ============================================================================> FreeBSD-EN-19:05.kqueue Errata Notice > The FreeBSD Project > > Topic: kqueue race condition and kernel panic > > Category: core > Module: kqueue > Announced: 2019-01-09 > Credits: Mark Johnston > Affects: FreeBSD 11.2 > Corrected: 2019-11-24 17:11:47 UTC (stable/11, 11.2-STABLE)Should this be 2018 or is this yet in the future?> 2019-01-09 18:57:38 UTC (releng/11.2, 11.2-RELEASE-p8) >[...] -- Cheers, Cy Schubert <Cy.Schubert at cschubert.com> FreeBSD UNIX: <cy at FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.
Shawn Webb
2019-Feb-05 19:54 UTC
[FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-19:05.kqueue
On Wed, Jan 09, 2019 at 07:40:30PM +0000, FreeBSD Errata Notices wrote:> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > ============================================================================> FreeBSD-EN-19:05.kqueue Errata Notice > The FreeBSD Project > > Topic: kqueue race condition and kernel panic > > Category: core > Module: kqueue > Announced: 2019-01-09 > Credits: Mark Johnston > Affects: FreeBSD 11.2 > Corrected: 2019-11-24 17:11:47 UTC (stable/11, 11.2-STABLE)Corrected November of 2018 or 2019? ;) -- Shawn Webb Cofounder and Security Engineer HardenedBSD Tor-ified Signal: +1 443-546-8752 Tor+XMPP+OTR: lattera at is.a.hacker.sx GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: <http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20190205/27202986/attachment.sig>