linux-kernel - Re: [PATCH] namespace:unmount pid_namespace's proc_mnt when copy_net

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 02 Nov 2012 17:02:37 +0800
From:	Gao feng <gaofeng@...fujitsu.com>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
CC:	linux-kernel@...r.kernel.org, containers@...ts.linux-foundation.org
Subject: Re: [PATCH] namespace:unmount pid_namespace's proc_mnt when copy_net_ns
 failed

于 2012年11月02日 16:54, Eric W. Biederman 写道:
> Gao feng <gaofeng@...fujitsu.com> writes:
> 
>> 于 2012年11月02日 15:02, Eric W. Biederman 写道:
>>> Gao feng <gaofeng@...fujitsu.com> writes:
>>>
>>>> we should call pid_ns_release_proc to unmount pid_namespace's
>>>> proc_mnt when copy_net_ns failed in function create_new_namespaces.
>>>>
>>>> otherwise,the proc_mnt will not be freed and because the super_block
>>>> of proc_mnt also add the reference of the pid_namespace,so this
>>>> pid_namespace will never be released too.
>>>
>>> Ouch!
>>>
>>> Have you encountered this failure in practice or is this just from
>>> review?
>>
>> I add some printk in pid_ns_release_proc,it's not called in above case.
>> when copy_net_ns failed,this pid_namespace is not used by any task,
>> so proc_flush_task can't call pid_ns_release_proc to umount this pidns->proc_mnt.
>> it's the only chance we can unmount this pindns->proc_mnt.
>>
>> With this patch,everything runs well.
> 
> I have reviewed the code and I don't doubt that this is necessary.
> 
> What caused you to look into this failure?  Is there some semi-practical
> real world case that someone is hitting?
> 

So far,there is no case hitting this problem.
Thanks

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/