From owner-freebsd-current@FreeBSD.ORG Tue Nov 11 01:27:13 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CA6B116A4CE for ; Tue, 11 Nov 2003 01:27:13 -0800 (PST) Received: from smtp01.syd.iprimus.net.au (smtp01.syd.iprimus.net.au [210.50.30.52]) by mx1.FreeBSD.org (Postfix) with ESMTP id D1DC944030 for ; Tue, 11 Nov 2003 01:27:12 -0800 (PST) (envelope-from tim@robbins.dropbear.id.au) Received: from robbins.dropbear.id.au (210.50.38.16) by smtp01.syd.iprimus.net.au (7.0.020) id 3F8B009E00AF5443 for current@freebsd.org; Tue, 11 Nov 2003 20:27:11 +1100 Received: by robbins.dropbear.id.au (Postfix, from userid 1000) id 30B286111; Tue, 11 Nov 2003 20:27:14 +1100 (EST) Date: Tue, 11 Nov 2003 20:27:13 +1100 From: Tim Robbins To: current@freebsd.org Message-ID: <20031111092713.GA698@wombat.robbins.dropbear.id.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Subject: tun + bpf = busted X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Nov 2003 09:27:13 -0000 With INVARIANTS enabled, I get a kernel panic when I run tcpdump on a "tun" interface. The message is "tunoutput: attempted use of a free mbuf!". This occurs because tun creates temporary mbufs on the stack and does not initialize m_flags, so it may or may not have the M_FREELIST bit set depending on what junk is on the stack. This seems to affect a whole bunch of other network drivers too. Tim