From owner-freebsd-security@freebsd.org Sun Jan 31 02:13:37 2016 Return-Path: Delivered-To: freebsd-security@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 73485A747B4 for ; Sun, 31 Jan 2016 02:13:37 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 63CECD04 for ; Sun, 31 Jan 2016 02:13:37 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u0V2Dasd068840 for ; Sun, 31 Jan 2016 02:13:37 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-security@FreeBSD.org Subject: [Bug 206761] Kernel stack overflow in sysctl handler for kern.binmisc.add Date: Sun, 31 Jan 2016 02:13:37 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: needs-patch, needs-qa, security X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: johannes@jo-t.de X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: 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-Mailman-Approved-At: Sun, 31 Jan 2016 02:36:35 +0000 X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Jan 2016 02:13:37 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D206761 johannes@jo-t.de changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |johannes@jo-t.de --- Comment #5 from johannes@jo-t.de --- Is this also missing a sx_xunlock(&interp_list_sx) for the ENOMEM error cas= e? --=20 You are receiving this mail because: You are on the CC list for the bug.= From owner-freebsd-security@freebsd.org Sun Jan 31 10:04:36 2016 Return-Path: Delivered-To: freebsd-security@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 00F0EA739BC for ; Sun, 31 Jan 2016 10:04:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E59031AB3 for ; Sun, 31 Jan 2016 10:04:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u0VA4ZKH053619 for ; Sun, 31 Jan 2016 10:04:35 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-security@FreeBSD.org Subject: [Bug 206761] Kernel stack overflow in sysctl handler for kern.binmisc.add Date: Sun, 31 Jan 2016 10:04:35 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: needs-patch, needs-qa, security X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: cturt@hardenedbsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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-Mailman-Approved-At: Sun, 31 Jan 2016 12:20:52 +0000 X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Jan 2016 10:04:36 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D206761 --- Comment #6 from CTurt --- I didn't even notice this before, but you're right. imgact_binmisc_add_entry: sx_xlock(&interp_list_sx); if (imgact_binmisc_find_entry(xbe->xbe_name) !=3D NULL) { sx_xunlock(&interp_list_sx); return (EEXIST); } /* Preallocate a new entry. */ ibe =3D imgact_binmisc_new_entry(xbe); if (!ibe) return (ENOMEM); SLIST_INSERT_HEAD(&interpreter_list, ibe, link); interp_list_entry_count++; sx_xunlock(&interp_list_sx); If the code ever reaches `return (ENOMEM);`, it is missing an `sx_xunlock(&interp_list_sx);` call. Unfortunately, this bug isn't triggerable, because `imgact_binmisc_add_entr= y` uses `M_WAITOK` for its allocations, and so can never return `NULL`: static imgact_binmisc_entry_t * imgact_binmisc_new_entry(ximgact_binmisc_entry_t *xbe) { ibe =3D malloc(sizeof(*ibe), M_BINMISC, M_WAITOK|M_ZERO); ... return (ibe); } My recommendation is to just remove the following check altogether: if (!ibe) return (ENOMEM); --=20 You are receiving this mail because: You are on the CC list for the bug.=