From owner-freebsd-bugs@freebsd.org Sat Sep 14 00:28:51 2019 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 9E492D739A for ; Sat, 14 Sep 2019 00:28:51 +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 46VYJz3j09z4HXM for ; Sat, 14 Sep 2019 00:28:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 7CF92D7399; Sat, 14 Sep 2019 00:28:51 +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 7BA4BD7398 for ; Sat, 14 Sep 2019 00:28:51 +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) server-signature RSA-PSS (4096 bits) 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 46VYJz2T6Jz4HXL for ; Sat, 14 Sep 2019 00:28:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 1E24EF8F1 for ; Sat, 14 Sep 2019 00:28:51 +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 x8E0SpwE013815 for ; Sat, 14 Sep 2019 00:28:51 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x8E0Spqx013809 for bugs@FreeBSD.org; Sat, 14 Sep 2019 00:28:51 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 240573] sysctl() does not return ENOMEM but silently truncate return data Date: Sat, 14 Sep 2019 00:28:30 +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 Some People X-Bugzilla-Who: rozhuk.im@gmail.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: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Sep 2019 00:28:51 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D240573 Bug ID: 240573 Summary: sysctl() does not return ENOMEM but silently truncate return data Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: rozhuk.im@gmail.com int mib[4] =3D { CTL_KERN, KERN_PROC, KERN_PROC_FILEDESC, getpid() }; if (0 !=3D sysctl(mib, 4, NULL, &buf_size, NULL, 0)) return (errno); buf =3D malloc(buf, buf_size); newfd =3D open("/dev/null", O_RDONLY); /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!= !! */ if (0 !=3D sysctl(mib, 4, buf, &buf_size, NULL, 0)) { if (ENOMEM !=3D errno) { free(buf) return (errno); } } This code should fail, but it fill buf with struct kinfo_file, and there is= no newfd. No fail, no error code set, silent data truncation. Probably sys/kern/kern_descrip.c: export_kinfo_to_sb() ... if (efbuf->remainder < kif->kf_structsize) { /* Terminate export. */ efbuf->remainder =3D 0; return (0); } ... should return here ENOMEM!? I see hack to avoid missing fd for that in lib/libutil/kinfo_getfile.c: kinfo_getfile(): ... len =3D len * 4 / 3; ... Same for kern.ipc.posix_shm_list. sys/kern/uipc_shm.c: sysctl_posix_shm_list() if (req->oldptr !=3D NULL && kif.kf_structsize + curlen > req->oldlen) break; error =3D ENOMEM; - before break missed. hack: usr.bin/posixshmcontrol/posixshmcontrol.c: list_shm() sys/kern/kern_proc.c: kern_proc_vmmap_out() ... /* Halt filling and truncate rather than exceeding maxlen */ if (maxlen !=3D -1 && maxlen < kve->kve_structsize) { error =3D 0; vm_map_lock_read(map); break; ... error =3D ENOMEM;? And probably other places where exist buf size check and exit from loop bef= ore call sbuf_bcat(). --=20 You are receiving this mail because: You are the assignee for the bug.=