From: Stefan Metzmacher <metze@samba.org>
To: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Victor Stewart <v@nametag.social>,
io-uring <io-uring@vger.kernel.org>,
Luke Hsiao <lukehsiao@google.com>,
"David S. Miller" <davem@davemloft.net>,
Jann Horn <jannh@google.com>, Arjun Roy <arjunroy@google.com>,
netdev <netdev@vger.kernel.org>, Jens Axboe <axboe@kernel.dk>
Subject: Re: [RFC 0/1] whitelisting UDP GSO and GRO cmsgs
Date: Mon, 30 Nov 2020 16:05:35 +0100 [thread overview]
Message-ID: <ebaa91f1-57c7-6c75-47a9-7e21360be2af@samba.org> (raw)
In-Reply-To: <CACSApvZW-UN9_To0J-bO6SMYKJgF9oFvsKk14D-7Tx4zzc8JUw@mail.gmail.com>
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Hi Soheil,
> Thank you for CCing us.
>
> The reason for PROTO_CMSG_DATA_ONLY is explained in the paragraph
> above in the commit message. PROTO_CMSG_DATA_ONLY is basically to
> allow-list a protocol that is guaranteed not to have the privilege
> escalation in https://crbug.com/project-zero/1975. TCP doesn't have
> that issue, and I believe UDP doesn't have that issue either (but
> please audit and confirm that with +Jann Horn).
>
> If you couldn't find any non-data CMSGs for UDP, you should just add
> PROTO_CMSG_DATA_ONLY to inet dgram sockets instead of introducing
> __sys_whitelisted_cmsghdrs as Stefan mentioned.
Was there a specific reason why you only added the PROTO_CMSG_DATA_ONLY check
in __sys_recvmsg_sock(), but not in __sys_sendmsg_sock()?
metze
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next prev parent reply other threads:[~2020-11-30 15:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 15:29 [RFC 0/1] whitelisting UDP GSO and GRO cmsgs Victor Stewart
2020-11-23 16:13 ` Stefan Metzmacher
[not found] ` <CAM1kxwhUcXLKU=2hCVaBngOKRL_kgMX4ONy9kpzKW+ZBZraEYw@mail.gmail.com>
[not found] ` <5d71d36c-0bfb-a313-07e8-0e22f7331a7a@samba.org>
2020-11-28 19:03 ` Victor Stewart
2020-11-30 10:52 ` Stefan Metzmacher
2020-11-30 14:57 ` Soheil Hassas Yeganeh
2020-11-30 15:05 ` Stefan Metzmacher [this message]
2020-11-30 15:15 ` Soheil Hassas Yeganeh
2020-11-30 16:17 ` Victor Stewart
2020-11-30 16:20 ` Soheil Hassas Yeganeh
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