[Lguest] [PATCH 4/5] lguest: use KVM hypercalls

[Matias Zabaljauregui]

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 <ebiederm at xmission.com>
> 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 <kaber at trash.net>
>