From: Jamal Hadi Salim <jhs@mojatatu.com>
To: Al Viro <viro@ZenIV.linux.org.uk>, Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Cong Wang <xiyou.wangcong@gmail.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
Network Development <netdev@vger.kernel.org>
Subject: Re: [PATCH] net: sched: Fix memory exposure from short TCA_U32_SEL
Date: Mon, 27 Aug 2018 07:57:58 -0400 [thread overview]
Message-ID: <cb9d4e74-3498-48bd-45e0-05e925dbdb5b@mojatatu.com> (raw)
In-Reply-To: <20180826225749.GY6515@ZenIV.linux.org.uk>
On 2018-08-26 6:57 p.m., Al Viro wrote:
> On Sun, Aug 26, 2018 at 06:32:37PM +0100, Al Viro wrote:
>
>> As far as I can tell, the solution is
> [snip long and painful reasoning]
>> pointers, and not in provably opaque fashion. Theoretically, the three tcf_...
>> inlines above need another look; fortunately, they don't use ->next at all, not to
>> mention not being used anywhere outside of net/sched/*.c
>>
>> The 80 lines above prove that we only need to grep net/sched/*.c for
>> tcf_proto_ops method calls. And only because we don't have (thank $DEITY)
>> anything that could deconstruct types - as soon as some bastard grows means
>> to say "type of the second argument of the function pointed to by p", this
>> kind of analysis, painful as it is, goes out of window. Even as it is,
>> do you really like the idea of newbies trying to get through the exercises
>> like the one above?
>
> BTW, would there be any problem if we took the definitions of tcf_proto and
> tcf_proto_ops to e.g. net/sched/tcf_proto.h (along with the three inlines in
> in pkt_cls.h), left forwards in sch_generic.h and added includes of "tcf_proto.h"
> where needed in net/sched/*.c?
>
I cant think of any challenges. Cong/Jiri? Would it require development
time classifiers/actions/qdiscs to sit in that directory (I suspect you
dont want them in include/net).
BTW, the idea of improving grep-ability of the code by prefixing the
ops appropriately makes sense. i.e we should have ops->cls_init,
ops->act_init etc.
cheers,
jamal
> That would make tcf_proto/tcf_proto_ops opaque outside of net/sched, reducing
> the exposure of internals. Something like a diff below (against net/master,
> builds clean, ought to result in identical binary):
>
next prev parent reply other threads:[~2018-08-27 11:58 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-26 5:58 [PATCH] net: sched: Fix memory exposure from short TCA_U32_SEL Kees Cook
2018-08-26 6:15 ` Al Viro
2018-08-26 6:19 ` Kees Cook
2018-08-26 17:30 ` Jamal Hadi Salim
2018-08-26 21:56 ` Kees Cook
2018-08-27 11:46 ` Jamal Hadi Salim
2018-08-27 14:08 ` Kees Cook
2018-08-27 14:26 ` Roman Mashak
2018-08-26 17:32 ` Al Viro
2018-08-26 18:57 ` Joe Perches
2018-08-26 21:24 ` Al Viro
2018-08-26 22:26 ` Joe Perches
2018-08-26 22:43 ` Al Viro
2018-08-27 2:00 ` Julia Lawall
2018-08-27 2:35 ` Al Viro
2018-08-27 3:35 ` Julia Lawall
2018-08-27 4:04 ` Al Viro
2018-08-27 4:41 ` Julia Lawall
2018-08-27 1:59 ` Julia Lawall
2018-08-26 22:57 ` Al Viro
2018-08-27 11:57 ` Jamal Hadi Salim [this message]
2018-08-27 21:31 ` Cong Wang
2018-08-28 0:03 ` Al Viro
2018-08-28 15:59 ` Al Viro
2018-08-31 4:03 ` Al Viro
2018-08-29 19:07 ` Cong Wang
2018-08-29 21:33 ` Al Viro
2018-08-26 21:22 ` David Miller
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