netdev - Re: IPv6 extension header privileges

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Date:	Fri, 27 May 2016 12:37:47 +0900
From:	YOSHIFUJI Hideaki <hideaki.yoshifuji@...aclelinux.com>
To:	Tom Herbert <tom@...bertland.com>,
	Linux Kernel Network Developers <netdev@...r.kernel.org>,
	Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>
Cc:	hideaki.yoshifuji@...aclelinux.com
Subject: Re: IPv6 extension header privileges

Hi,

Tom Herbert wrote:
> Hi,
> 
> In ipv6_sockglue.c I noticed:
> 
> /* hop-by-hop / destination options are privileged option */
> retv = -EPERM;
> if (optname != IPV6_RTHDR && !ns_capable(net->user_ns, CAP_NET_RAW))
>            break;
> 
> Can anyone provide that rationale as to why these are privileged ops?

It is better to disallow by default for security.
FreeBSD does this in the same way.
We may have sysctl bitmaps, of course.

--yoshfuji

> 
> Thanks,
> Tom
> 

-- 
Hideaki Yoshifuji <hideaki.yoshifuji@...aclelinux.com>
Technical Division, MIRACLE LINUX CORPORATION