From owner-freebsd-bugs@freebsd.org Fri Oct 9 13:35:58 2020 Return-Path: Delivered-To: freebsd-bugs@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 35A773FAF4F for ; Fri, 9 Oct 2020 13:35:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 4C78Gk0jxHz4PFS for ; Fri, 9 Oct 2020 13:35:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 16E8E3FAF4E; Fri, 9 Oct 2020 13:35:58 +0000 (UTC) Delivered-To: bugs@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 16B063FB01B for ; Fri, 9 Oct 2020 13:35:58 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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 "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4C78Gj6xznz4PCh for ; Fri, 9 Oct 2020 13:35:57 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id B3DC61A634 for ; Fri, 9 Oct 2020 13:35:57 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 099DZv8I002504 for ; Fri, 9 Oct 2020 13:35:57 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 099DZv9l002503 for bugs@FreeBSD.org; Fri, 9 Oct 2020 13:35:57 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 250222] Multiple ways for a kernel DoS (ufs_lookup_ino) Date: Fri, 09 Oct 2020 13:35:57 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: emaste@freebsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Oct 2020 13:35:58 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D250222 Bug ID: 250222 Summary: Multiple ways for a kernel DoS (ufs_lookup_ino) Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: emaste@freebsd.org Reported by: Christopher Krah of Fraunhofer FKIE Reporter's ID: FS-15-UFS-4 *Description of the vulnerability*: Mounting a specially crafted UFS filesy= stem may lead to a kernel Denial of Service that was already anticipated in the code. This is due to the following code in function ufs_dirbad in line 762 in /usr/src/sys/ufs/ufs/ufs_lookup.c: { struct mount *mp; mp =3D ITOV(ip)->v_mount; if ((mp->mnt_flag & MNT_RDONLY) =3D=3D 0) panic("ufs_dirbad: %s: bad dir ino %ju at offset %ld: %s", mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, (long)offset, how); else (void)printf("%s: bad dir ino %ju at offset %ld: %s\n", mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, (long)offset, how); } So far we were able to trigger this panic via 5 different system calls and hence different/multiple unique back traces as of time of writing this emai= l: * sys_mkdir * sys_openat * sys_fsstatat * sys_access * sys_mknodat This shows that the UFS fs is especially vulnerable to this type of kernel = DoS. If additional different ways to trigger this behavior appear they will be a= dded to the same shared folder referenced here at [1]. *Affected versions*: tested with FreeBSD 12.0-RELEASE AMD64.=20 *Workaround*: None --- FS image to be attached. --=20 You are receiving this mail because: You are the assignee for the bug.=