From owner-freebsd-bugs@freebsd.org Sat Jan 9 10:35:15 2021 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 854ED4D03BB for ; Sat, 9 Jan 2021 10:35:15 +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 4DCbvl39s4z4nfr for ; Sat, 9 Jan 2021 10:35:15 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 6B4524D0719; Sat, 9 Jan 2021 10:35:15 +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 6B0A74D06D7 for ; Sat, 9 Jan 2021 10:35:15 +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 4DCbvl2Hlfz4nYq for ; Sat, 9 Jan 2021 10:35:15 +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 41BE614654 for ; Sat, 9 Jan 2021 10:35:15 +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 109AZFMc063167 for ; Sat, 9 Jan 2021 10:35:15 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 109AZFvL063166 for bugs@FreeBSD.org; Sat, 9 Jan 2021 10:35:15 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 252542] cmp -s + regular files + skipping is broken Date: Sat, 09 Jan 2021 10:35:15 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: Unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: william@25thandclement.com 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: 2.1.34 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Jan 2021 10:35:15 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D252542 Bug ID: 252542 Summary: cmp -s + regular files + skipping is broken Product: Base System Version: Unspecified Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: william@25thandclement.com The file length comparison short-circuit in cmp.c for when the -s flag, reg= ular files, and SKIP1 are specified is broken. c_regular in regular.c had a simi= lar buggy short-circuit that was fixed in June 2000. But in July 2000 the -z fl= ag feature was added which accidentally reintroduced the same bug. The bug is comparing the file sizes without accounting for skip1 and skip2. See https://svnweb.freebsd.org/base/head/usr.bin/cmp/cmp.c?revision=3D344551&vi= ew=3Dmarkup#l193 Note that both sflag and zflag are set when -s is specified.=20 Discovered when investigating a bug report on the OpenBSD mailing-list. More detailed dissection at https://marc.info/?l=3Dopenbsd-misc&m=3D161017967207= 304&w=3D2 --=20 You are receiving this mail because: You are the assignee for the bug.=