From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matias Zabaljauregui Subject: Re: [PATCH 4/5] lguest: use KVM hypercalls Date: Mon, 13 Apr 2009 13:29:40 -0300 Message-ID: <1239640180.31741.12.camel@zetabook> References: <200903271022.38244.rusty@rustcorp.com.au> <1238709324.5823.8.camel@odie.local> <1239043798.27826.93.camel@zetabook> <200904081021.39877.rusty@rustcorp.com.au> <1239224319.17844.16.camel@zetabook> <49DDE91A.8060603@trash.net> <49DDF614.1060909@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <49DDF614.1060909-dcUjhNyLwpNeoWH0uzbU5w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: lguest-bounces+glkvl-lguest=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org Errors-To: lguest-bounces+glkvl-lguest=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org To: Patrick McHardy Cc: lguest-mnsaURCQ41sdnm+yROfE0A@public.gmane.org, "Eric W. Biederman" , virtualization-qjLDD68F18O7TbgM5vRIOg@public.gmane.org List-Id: virtualization@lists.linuxfoundation.org Hello Patrick, On Thu, 2009-04-09 at 15:20 +0200, Patrick McHardy wrote: > Patrick McHardy wrote: > > which goes away by turning of CONFIG_STACKPROTECTOR. Now it seems > > to work, but the host crashes before the guests are fully up somewhere > > in the tun-device. I couldn't capture the oops yet, but I'll try > > to fix it myself. > > This was caused by a local change of mine to attach to existing > tun-devices, combined with a bug in the tun driver, which looks > like it was introduced by this patch: > > commit c70f182940f988448f3c12a209d18b1edc276e33 > Author: Eric W. Biederman > Date: Tue Jan 20 11:07:17 2009 +0000 > > tun: Fix races between tun_net_close and free_netdev. > So, can we assume that everything is ok if we turn off STACK_PROTECTOR ? thanks Matias > When creating the device using tunctl the sk->sk_sleep poiner is > set to the read_wait completion of the file opened by tunctl, but > it is not refreshed when attaching to lguest or released when > closing the file, causing a stale pointer dereference in > tun_sock_write_space(). > > Eric, please review. Thanks. > > Signed-off-by: Patrick McHardy >