From: Jamal Hadi Salim <jhs@mojatatu•com>
To: "Eric W. Biederman" <ebiederm@xmission•com>,
David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org, alexander.h.duyck@intel•com
Subject: Re: [PATCH 0/2] net_sched: Remove broken tc actions
Date: Sun, 27 Oct 2013 12:58:38 -0400 [thread overview]
Message-ID: <526D463E.6040000@mojatatu.com> (raw)
In-Reply-To: <87fvrmu909.fsf@xmission.com>
On 10/27/13 09:40, Eric W. Biederman wrote:
>
> While auditing the code to make certain it would be safe to enable the
> user namespace root to use tc actions I stumbled on the strange fact
> that two of the tc modules in the kernel have been broken for more
> years than I care to think about.
>
> In particular neither of these two modules implements the tc_action_ops
> lookup method. Which means that in practice neither RTM_GETACTION nor
> RTM_DELACTION work. And with RTM_DELACTION broken that looks like a
> permanent leak of kernel memory to me.
>
>
> A leak I am not happy at root having and certainly not something I want
> to allow unprivileged users access to.
>
> On the premise that 5+ years is too long to wait for someone to notice,
> complain and get this code fixed let's just remove these broken tc
> modules.
>
Nah, dude.
You dont have to implement the get/del. Actions are typically bound
to filters; when the filters disappears the action is destroyed.
You Get the filter, you Get the bound actions.
you can add actions without filters - but in such a case, for both
of these ones you picked, you can dump or flush them unless they are
bound to a filter. Thats the minimal requirement (which is met).
What is your use case to need explicit get/del?
Given act_simple is pedagogical in nature, I think
that will be useful for illustration purposes.
cheers,
jamal
next prev parent reply other threads:[~2013-10-27 16:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-27 13:40 [PATCH 0/2] net_sched: Remove broken tc actions Eric W. Biederman
2013-10-27 13:42 ` [PATCH 1/2] net_sched: Remove broken act_skbedit Eric W. Biederman
2013-10-27 13:43 ` [PATCH 2/2] net_sched: Remove broken act_simple Eric W. Biederman
2013-10-27 16:58 ` Jamal Hadi Salim [this message]
2013-10-27 20:37 ` [PATCH 0/2] net_sched: Remove broken tc actions Alexander Duyck
2013-10-28 22:57 ` Jamal Hadi Salim
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