From owner-freebsd-bugs@FreeBSD.ORG Mon May 14 23:00:13 2007 Return-Path: X-Original-To: freebsd-bugs@hub.freebsd.org Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 52A7B16A408 for ; Mon, 14 May 2007 23:00:13 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [69.147.83.40]) by mx1.freebsd.org (Postfix) with ESMTP id 349A013C46E for ; Mon, 14 May 2007 23:00:13 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.4/8.13.4) with ESMTP id l4EN0Dpj016674 for ; Mon, 14 May 2007 23:00:13 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.4/8.13.4/Submit) id l4EN0D2P016673; Mon, 14 May 2007 23:00:13 GMT (envelope-from gnats) Resent-Date: Mon, 14 May 2007 23:00:13 GMT Resent-Message-Id: <200705142300.l4EN0D2P016673@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, Ludovico Gardenghi Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D86E316A403 for ; Mon, 14 May 2007 22:59:54 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [69.147.83.33]) by mx1.freebsd.org (Postfix) with ESMTP id C9BA313C448 for ; Mon, 14 May 2007 22:59:54 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.13.1/8.13.1) with ESMTP id l4EMxsYE020796 for ; Mon, 14 May 2007 22:59:54 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.13.1/8.13.1/Submit) id l4EMsrYI020438; Mon, 14 May 2007 22:54:53 GMT (envelope-from nobody) Message-Id: <200705142254.l4EMsrYI020438@www.freebsd.org> Date: Mon, 14 May 2007 22:54:53 GMT From: Ludovico Gardenghi To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.0 Cc: Subject: kern/112672: [if_tap] stat /dev/tapN leads to panic for N >= 2G X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 May 2007 23:00:13 -0000 >Number: 112672 >Category: kern >Synopsis: [if_tap] stat /dev/tapN leads to panic for N >= 2G >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon May 14 23:00:12 GMT 2007 >Closed-Date: >Last-Modified: >Originator: Ludovico Gardenghi >Release: 6.2-RELEASE >Organization: Virtual Square Team >Environment: FreeBSD devil.localdomain 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Fri Jan 12 10:40:27 UTC 2007 root@dessler.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC i386 >Description: Trying to access a tap device in /dev leads to a kernel panic ("foo") if the tap name is tapN when N is greater or equal than 2^31 and less than 2^32-1. This is probably due to a bad conversion between unsigned and signed in dev_stdclone (kern_conf.c:750). The tap name is converted from string to integer with a loop (lines 762--765) and stored in the signed int variable 'u'; if the resulting value is greater than 2G, u becomes negative and the check at line 766 (if (u > 0xffffff)) fails, but the original value is in fact greater than that value and should be rejected. >How-To-Repeat: shammash@devil:~$ ls -l /dev/tap2147483648 (the following is in /var/log/messages) May 10 13:57:12 devil kernel: dev 0xc370a000 (tap-1530494977) is on clonelist May 10 13:57:12 devil kernel: unit=-1530494977, low=0, extra=0x0 May 10 13:57:12 devil kernel: 0xc36b4b00 tap0 May 10 13:57:12 devil kernel: 0xc36f1500 tap255 May 10 13:57:12 devil kernel: 0xc34f2000 tap256 May 10 13:57:12 devil kernel: 0xc32aee00 tap65537 May 10 13:57:12 devil kernel: 0xc36f1a00 tap1 May 10 13:57:12 devil kernel: 0xc36f1600 tap2 May 10 13:57:12 devil kernel: 0xc370a000 tap-1530494977 May 10 13:57:12 devil kernel: panic: foo May 10 13:57:12 devil kernel: Uptime: 35m24s May 10 13:57:12 devil kernel: Cannot dump. No dump device defined. May 10 13:57:12 devil kernel: Automatic reboot in 15 seconds - press a key on the console to abort May 10 13:57:12 devil kernel: Rebooting... >Fix: It should be enough to change 'int' to 'unsigned int' inside the functions involved in tap creation, mainly dev_stdclone() in kern/kern_conf.c. >Release-Note: >Audit-Trail: >Unformatted: