From owner-freebsd-bugs@freebsd.org Thu Jun 4 15:31:49 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 70C9E2F7846 for ; Thu, 4 Jun 2020 15:31:49 +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 49d8s12QYHz465t for ; Thu, 4 Jun 2020 15:31:49 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 530F72F7845; Thu, 4 Jun 2020 15:31:49 +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 524492F7844 for ; Thu, 4 Jun 2020 15:31:49 +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 49d8s11Yvnz46B2 for ; Thu, 4 Jun 2020 15:31:49 +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 3119B21B94 for ; Thu, 4 Jun 2020 15:31:49 +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 054FVnMF084216 for ; Thu, 4 Jun 2020 15:31:49 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 054FVnTJ084215 for bugs@FreeBSD.org; Thu, 4 Jun 2020 15:31:49 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 246983] sbput(3) writes out the values of pointers verbatim Date: Thu, 04 Jun 2020 15:31:49 +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: Unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: goatshit54108@national.shitposting.agency 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: Thu, 04 Jun 2020 15:31:49 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D246983 Bug ID: 246983 Summary: sbput(3) writes out the values of pointers verbatim Product: Base System Version: Unspecified Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: goatshit54108@national.shitposting.agency `struct fs` contains some pointer fields. The binary representation of a `struct fs` is written out verbatim to the disk: see ffs_sbput() in sys/ufs/ffs/ffs_subr.c. This inadvertently causes garbage to be stored, in particular by newfs(1). (It is garbage because those pointers pointed to the then-current stack or heap.) Although a mere pointer doesn't reveal anything useful (like a part of a private key) to an attacker, garbage output deteriorates reproducibility. In an attempt to work around this design, users of sbput(3) ought to zero o= ut those pointer fields, but this isn't totally possible, because the function makes use of the `fs_csp` field. So the solution should be to save the poin= ters before writing the whole struct out, and to restore them afterwards. It would have been ideal if `struct fs` didn't contain any pointers at all. --=20 You are receiving this mail because: You are the assignee for the bug.=