From owner-freebsd-security@freebsd.org Wed Sep 2 17:45:58 2020 Return-Path: Delivered-To: freebsd-security@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B8BB23DE8C6 for ; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2610:1c1:1:6074::16:84]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "freefall.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BhWZG3NZDz3bFF; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) (envelope-from security-advisories@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068758; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=B+JyZ1omRR/4OG3IUGrw8uGoMffGrzMCvg1PmGCd5Oo=; b=ZoqFa1YSdaDX/b17vPgB55Dc47nLXI/vppcd/fhtcXubV04I5DHAvglSdo8DWtoFSiKbUZ L9HcrjwaJ8boSx9kqdjapZT9MUEyKB/oKLNkSHuZ3rPkW2fZ2LZIkmV1nKM41KPA0Y/fSR 3gf3BKcPN085kCZPgTvq7fq1Galhe86d50GfuaRy4o7nia4zXi/IAQMdQpuPNIK8HnMWDL +rl+QbxgFvdeguTDpItSopQMRNtsh7vqrZFi+9LduoUIf8IZvQTGoXU3DC9sx90Lk6+7Zc 6xBHi5j8wlUlEm/cd8ySLn3xEBQwxXOdNwGfGEKt500YU7Gtsol8d0tnP3z0vw== Received: by freefall.freebsd.org (Postfix, from userid 945) id 3B6CACA27; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory FreeBSD-SA-20:25.sctp Reply-To: freebsd-security@freebsd.org Precedence: bulk Message-Id: <20200902174558.3B6CACA27@freefall.freebsd.org> Date: Wed, 2 Sep 2020 17:45:58 +0000 (UTC) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068758; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=B+JyZ1omRR/4OG3IUGrw8uGoMffGrzMCvg1PmGCd5Oo=; b=j+3xGdKftSgP8j+TnNg/Y2dRH/gycmH9Bkfu7yqtTKwCbsHo6k8W4a86XhlKpbjR4OMSH3 bE/qovbkBqFvTBr1dSa32HGwwzO/H+uXWzZOR8PDT9Y1MNKOqjHjUFdON7ldop9m0D6PZr ZVvABGjjx3gvmAgUAyhFHTI7UprYtN9TZo4/XITbGcXn+FQrBe7HgjQAITADjVGZzC07Lt 9GyHW/8VNDg88nfp/wi1qNoRm7Dz5VPEiWqm0KuqvzFFLJWIZdgpb0vvftbJPJOFmum29s xNjCkxSPAG8asC6nKjGBBs3iEDZR1IaaiNyotd2R1forcKLHpS3i/VJqR7mIfA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1599068758; a=rsa-sha256; cv=none; b=kPp/RKvQgQau/2gC6bSA+zg2k3IQEt0ASOcLqvJFtQooRsaFPeMbthNd5qQiS9vWzquwpu E8aPc9XFTF8APi5HwimlybNxExzTNzpwsHQdCrKRTKcq6sFe9nR2+xTx+BsS55GISgg0NV PCZ7DxZMGXbHSQhIpfZcuHqbvmnYpj2Jm36jqRRF47xh2AP8eYVcSpT/kAzFjsvywhI+kz qjhLsUtRU2pXT2+NSxOfmGe16ZLvsk0gbeTHZS6CTRu0+UUTu39lPJxm5ac2plHT2jVTZS 9xeVZMi7IdCJhknCdiC+yB9/wnkFY0q2sQWPUlV3wrVeTyECqjdwFNsQpyYF9A== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.33 List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Sep 2020 17:45:58 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:25.sctp Security Advisory The FreeBSD Project Topic: SCTP socket use-after-free bug Category: core Module: kernel Announced: 2020-09-02 Credits: Megan2013678@protonmail.com Affects: All supported versions of FreeBSD. Corrected: 2020-08-24 09:19:05 UTC (stable/12, 12.1-STABLE) 2020-09-02 16:24:32 UTC (releng/12.1, 12.1-RELEASE-p9) 2020-08-24 09:46:36 UTC (stable/11, 11.4-STABLE) 2020-09-02 16:24:32 UTC (releng/11.4, 11.4-RELEASE-p3) 2020-09-02 16:24:32 UTC (releng/11.3, 11.3-RELEASE-p13) CVE Name: CVE-2020-7463 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background The Stream Control Transmission Protocol (SCTP) is a message oriented transport protocol supporting arbitrary large user messages. It can be accessed from applications by using the the socket API. II. Problem Description Due to improper handling in the kernel, a use-after-free bug can be triggered by sending large user messages from multiple threads on the same socket. III. Impact Triggering the use-after-free situation may result in unintended kernel behaviour including a kernel panic. IV. Workaround No workaround is available. V. Solution Upgrade your vulnerable 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 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. [FreeBSD 12.1] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.12.1.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.12.1.patch.asc # gpg --verify sctp.12.1.patch.asc [FreeBSD 11.4] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.4.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.4.patch.asc # gpg --verify sctp.11.4.patch.asc [FreeBSD 11.3] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.3.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.3.patch.asc # gpg --verify sctp.11.3.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/ r364644 releng/12.1/ r365256 stable/11/ r364651 releng/11.4/ r365256 releng/11.3/ r365256 - ------------------------------------------------------------------------- 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/A6HiuWv54gCjWNV05eS9J6n5cIFAl9PzTZfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cIMPw//ZOYh7TQdwvreQ/iZbJphPp7hBVJqFWPE9M72Yfo87/vkl+T5/GW9wiLT MQlknQ7SDyzE7i8RpGvX0lmXLbr1e2rkvin1ZFdCbWkPzC7w0WVH7XX6+I+RJmkh E4dtmHrYhLRwmVtW5WYZdfO+iYVTJl/h43eYbYvNgJZSuKkvl2Vk6DqyseHx7xR6 gc7/41AIpMiqRLQI9ZnRvZCEiLq4G+q5z499ACfAutT9o+1T9L6QLCPuyY+fziiq cI2E/pQA5uxOY/z3ejKHeOzErjycY6GEhMiBKmsJqV6oU/cZd5hZ1qsmE9Xbi3/c Ax+OZr+Ve2a78dD7jOrmCrpBtG1Pg39c6VuQqHD3UN3seBNEkn4kto9vDX9fLceD GZbueV97boFxjnXu1B6C8ufqEZDqTaf/SU3+vCobBgydP+V8c1P5LbP6qcFHOUrk k7ijiJv03aYyY1Z6XtqbRsudZzIaTt+jneUA1eA46iWQqVZQHKo2liw5kAtsGu0k injGcazWRphV6xgOHIMCfrGcLLf0j+4UjiDUk30cansLGewuk/uEh6FlA4NzyRWA 4L3Q0l/XQWvO2sNMtF9LbBUUujDyy93Vy8BouSp59v7+bAYrRHfcIAmaQnE4jev2 BY7/JsrfQ9rG/Anzg49Hec8pw9VEvv4kA1STqXcpMt9Fq+0DslA= =2ET6 -----END PGP SIGNATURE-----