Re: [PATCH] lockd: lost rollback of set_grace_period() in lockd_down_net()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Applied for 4.15 and stable, thanks.--b.

On Thu, Nov 02, 2017 at 01:03:42PM +0300, Vasily Averin wrote:
> Commit efda760fe95ea ("lockd: fix lockd shutdown race") is incorrect,
> it removes lockd_manager and disarm grace_period_end for init_net only. 
> 
> If nfsd was started from another net namespace lockd_up_net() calls 
> set_grace_period() that adds lockd_manager into per-netns list
> and queues grace_period_end delayed work.
> 
> These action should be reverted in lockd_down_net().
> Otherwise it can lead to double list_add on after restart nfsd in netns,
> and to use-after-free if non-disarmed delayed work will be executed after netns destroy.  
> 
> Fixes commit efda760fe95e ("lockd: fix lockd shutdown race")
> 
> Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
> ---
>  fs/lockd/svc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
> index c1573860..809cbcc 100644
> --- a/fs/lockd/svc.c
> +++ b/fs/lockd/svc.c
> @@ -277,6 +277,8 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
>  	if (ln->nlmsvc_users) {
>  		if (--ln->nlmsvc_users == 0) {
>  			nlm_shutdown_hosts_net(net);
> +			cancel_delayed_work_sync(&ln->grace_period_end);
> +			locks_end_grace(&ln->lockd_manager);
>  			svc_shutdown_net(serv, net);
>  			dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net);
>  		}
> -- 
> 2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux