From owner-freebsd-bugs@FreeBSD.ORG Wed Oct 20 12:10:32 2004 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0475616A4CF for ; Wed, 20 Oct 2004 12:10:32 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id C5FBB43D2D for ; Wed, 20 Oct 2004 12:10:31 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.11/8.12.11) with ESMTP id i9KCAVKl045861 for ; Wed, 20 Oct 2004 12:10:31 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.11/8.12.11/Submit) id i9KCAVti045860; Wed, 20 Oct 2004 12:10:31 GMT (envelope-from gnats) Resent-Date: Wed, 20 Oct 2004 12:10:31 GMT Resent-Message-Id: <200410201210.i9KCAVti045860@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Andriy Gapon Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9707816A4CF for ; Wed, 20 Oct 2004 12:03:10 +0000 (GMT) Received: from www.freebsd.org (www.freebsd.org [216.136.204.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8A41543D62 for ; Wed, 20 Oct 2004 12:03:10 +0000 (GMT) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.12.11/8.12.11) with ESMTP id i9KC3APs096509 for ; Wed, 20 Oct 2004 12:03:10 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.12.11/8.12.11/Submit) id i9KC3Aff096506; Wed, 20 Oct 2004 12:03:10 GMT (envelope-from nobody) Message-Id: <200410201203.i9KC3Aff096506@www.freebsd.org> Date: Wed, 20 Oct 2004 12:03:10 GMT From: Andriy Gapon To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-2.3 Subject: kern/72922: linux emulation: suid/sgid threaded applications hang X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Oct 2004 12:10:32 -0000 >Number: 72922 >Category: kern >Synopsis: linux emulation: suid/sgid threaded applications hang >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Oct 20 12:10:31 GMT 2004 >Closed-Date: >Last-Modified: >Originator: Andriy Gapon >Release: 5.2.1-RELEASE-p11 >Organization: >Environment: 5.2.1-RELEASE-p11 i386 linux_base-7.1_7 linux_devtools-7.1_3 >Description: linux applications using old linux threads (pre-NPTL) use signal 32 (linux SIGRTMIN) for communication between thread-processes. If such an linux application is installed suid or sgid and security.bsd.conservative_signals=1 (default), then permission will be denied to send such a signal and the application will freeze. Please see http://docs.freebsd.org/cgi/getmsg.cgi?fetch=13492+0+archive/2004/freebsd-emulation/20041017.freebsd-emulation for an example and detailed investigation of such case. >How-To-Repeat: using the same environment as mine 1. make any threaded linux application suid 2. run it so that it really changes privileges 3. see it freeze >Fix: 1. either add signal 32 (linux SIGRTMIN) to list of "common signals" in cr_cansignal() 2. or detect the described situation in cr_cansignal() and produce a warning message explaining the situation and suggesting setting security.bsd.conservative_signals=0 >Release-Note: >Audit-Trail: >Unformatted: