From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Kirby Subject: Re: 3.3.0, 3.4-rc1 reproducible tun Oops Date: Mon, 16 Apr 2012 19:08:53 -0700 Message-ID: <20120417020852.GA18875@hostway.ca> References: <20120404220525.GD21505@hostway.ca> <1333593664.18626.577.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: Eric Dumazet , Stanislav Kinsbursky Return-path: Received: from peace.netnation.com ([204.174.223.2]:52992 "EHLO peace.netnation.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751523Ab2DQCIy (ORCPT ); Mon, 16 Apr 2012 22:08:54 -0400 Content-Disposition: inline In-Reply-To: <1333593664.18626.577.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Apr 05, 2012 at 04:41:04AM +0200, Eric Dumazet wrote: > Hmm, is it happening if you remove the nvidia module ? > > If yes, please try to add slub_debug=FZPU Finally got annoyed enough at this to bisect it. It doesn't happen every time and I got a bit confused, but I finally tracked it down to: 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d is the first bad commit commit 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d Author: Stanislav Kinsbursky Date: Mon Mar 12 02:59:41 2012 +0000 tun: don't hold network namespace by tun sockets v3: added previously removed sock_put() to the tun_release() callback, because sk_release_kernel() doesn't drop the socket reference. v2: sk_release_kernel() used for socket release. Dummy tun_release() is required for sk_release_kernel() ---> sock_release() ---> sock->ops->release() call. TUN was designed to destroy it's socket on network namesapce shutdown. But this will never happen for persistent device, because it's socket holds network namespace. This patch removes of holding network namespace by TUN socket and replaces it by creating socket in init_net and then changing it's net it to desired one. On shutdown socket is moved back to init_net prior to final put. Signed-off-by: Stanislav Kinsbursky Signed-off-by: David S. Miller ...With this reverted on top of 3.4-rc3, I no longer see crashes when I keep making and breaking the SSH tunnel while running "vmstat 1" in an SSH session over a socket that is running through that tunnel. Simon-