From: ebiederm@xmission.com (Eric W. Biederman)
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jann Horn <jann@thejh.net>,
"ksummit-discuss@lists.linuxfoundation.org"
<ksummit-discuss@lists.linuxfoundation.org>
Subject: Re: [Ksummit-discuss] [TOPIC] kernel hardening / self-protection / whatever
Date: Thu, 21 Jul 2016 12:03:31 -0500 [thread overview]
Message-ID: <87poq653fg.fsf@x220.int.ebiederm.org> (raw)
In-Reply-To: <20160720064228.GA32737@gondor.apana.org.au> (Herbert Xu's message of "Wed, 20 Jul 2016 14:42:28 +0800")
Herbert Xu <herbert@gondor.apana.org.au> writes:
> On Tue, Jul 19, 2016 at 09:14:03PM -0500, Eric W. Biederman wrote:
>> True. I tried to review things to make certain they were safe in user
>> namespaces when I enabled things but clearly a few things slipped
>> through the cracks.
>
> What's worse is that after you enable them someone else can come
> along and add a new piece of functionality but still assuming
> that only root has access to it. I encountered this with netfilter
> and rhashtable where the argument put forward was that as long as
> only root had access to a hash table then we don't have to worry
> about hash collissions.
Wow. I missed that hash table discussion.
Yes. People working on old assumptions is problematic. Although I have
seen people in code reviews ask the question and what happens if someone
enables your code with user namespaces? Which seems like a good sign.
Hopefully we can just retire the argument only root can do this, we
don't need to care about code quality.
Eric
next prev parent reply other threads:[~2016-07-21 17:16 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-11 4:28 Andy Lutomirski
2016-07-11 13:05 ` Rafael J. Wysocki
2016-07-11 16:30 ` Eric W. Biederman
2016-07-11 17:57 ` Kees Cook
2016-07-12 16:40 ` Eric W. Biederman
2016-07-21 15:54 ` Mark Rutland
2016-07-11 17:33 ` Jann Horn
2016-07-19 15:40 ` Eric W. Biederman
2016-07-20 2:14 ` Andy Lutomirski
2016-07-20 2:14 ` Eric W. Biederman
2016-07-20 6:42 ` Herbert Xu
2016-07-21 17:03 ` Eric W. Biederman [this message]
2016-07-11 17:53 ` Kees Cook
2016-07-11 18:07 ` Josh Triplett
2016-07-11 18:59 ` Kees Cook
2016-07-31 9:55 ` Paul Burton
2016-07-31 22:04 ` Kees Cook
2016-08-01 10:47 ` Mark Rutland
2016-08-01 19:42 ` Kees Cook
2016-08-03 22:53 ` Catalin Marinas
2016-08-04 5:32 ` Kees Cook
2016-08-04 5:45 ` Andy Lutomirski
2016-08-04 5:54 ` Kees Cook
2016-08-05 0:12 ` Andy Lutomirski
2016-09-08 23:54 ` Kees Cook
2016-09-09 0:42 ` Andy Lutomirski
2016-08-04 14:17 ` Dave Hansen
2016-08-04 22:29 ` Catalin Marinas
2016-08-01 9:34 ` [Ksummit-discuss] [nominations] " Mark Rutland
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