From owner-freebsd-bugs@FreeBSD.ORG Tue Mar 29 20:50:02 2005 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 A512E16A4CE for ; Tue, 29 Mar 2005 20:50:02 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5778943D2D for ; Tue, 29 Mar 2005 20:50:02 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.3/8.13.3) with ESMTP id j2TKo2PU091586 for ; Tue, 29 Mar 2005 20:50:02 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.3/8.13.1/Submit) id j2TKo2TX091585; Tue, 29 Mar 2005 20:50:02 GMT (envelope-from gnats) Resent-Date: Tue, 29 Mar 2005 20:50:02 GMT Resent-Message-Id: <200503292050.j2TKo2TX091585@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, Anjali Kulkarni Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3A5CB16A4CE for ; Tue, 29 Mar 2005 20:40:36 +0000 (GMT) Received: from www.freebsd.org (www.freebsd.org [216.136.204.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1822D43D45 for ; Tue, 29 Mar 2005 20:40:36 +0000 (GMT) (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 j2TKeZOC029550 for ; Tue, 29 Mar 2005 20:40:35 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.13.1/8.13.1/Submit) id j2TKeZ13029549; Tue, 29 Mar 2005 20:40:35 GMT (envelope-from nobody) Message-Id: <200503292040.j2TKeZ13029549@www.freebsd.org> Date: Tue, 29 Mar 2005 20:40:35 GMT From: Anjali Kulkarni To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-2.3 Subject: kern/79342: When looking for an unused port number for bind or connect, if low & high port range are equal, kernel can trap in divide by zero error 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: Tue, 29 Mar 2005 20:50:02 -0000 >Number: 79342 >Category: kern >Synopsis: When looking for an unused port number for bind or connect, if low & high port range are equal, kernel can trap in divide by zero error >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Tue Mar 29 20:50:01 GMT 2005 >Closed-Date: >Last-Modified: >Originator: Anjali Kulkarni >Release: 4.10 >Organization: Juniper Networks >Environment: 4.10-RELEASE-p2 >Description: In src/sys/netinet/in_pcb.c, in the function in_pcbbind(), when trying to find an unused port number in the range of ports allowed to be used, there are cases to handle upper port limit > lower port limit and upper port limit < lower port limit, but no case to handle when they are equal. Consequently, if they are equal, the kernel will have a divide by zero trap when the line *lastport = first - (arc4random() % (first - last)) OR the line *lastport = first + (arc4random() % (last - first)) is executed, where first and last are the port ranges in which we check for an unused port number. >How-To-Repeat: set net.inet.ip.portrange.first = net.inet.ip.portrange.last. (say 1024) Now do a bind or a connect with a port number of 0. >Fix: In in_pcbbind(), there should be a check for the case when first & last are equal as follows: /* * Simple check to ensure all ports are not used up causing * a deadlock here. * * We split the two cases (up and down) so that the direction * is not being tested on each round of the loop. */ + if (first == last) { + inp->inp_laddr.s_addr = INADDR_ANY; + return (EADDRNOTAVAIL); + } else if (first > last) { - if (first > last) { >Release-Note: >Audit-Trail: >Unformatted: