From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Kevin Cernekee <cernekee@chromium.org>
Cc: netfilter-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] netfilter: nfnetlink_cthelper: Add missing permission checks
Date: Mon, 4 Dec 2017 11:32:00 +0100 [thread overview]
Message-ID: <20171204103200.GA16022@salvia> (raw)
In-Reply-To: <1512331965-30830-1-git-send-email-cernekee@chromium.org>
On Sun, Dec 03, 2017 at 12:12:45PM -0800, Kevin Cernekee wrote:
> The capability check in nfnetlink_rcv() verifies that the caller
> has CAP_NET_ADMIN in the namespace that "owns" the netlink socket.
> However, nfnl_cthelper_list is shared by all net namespaces on the
> system.
Right, we need per-netns support for nfnetlink_cthelper.
> An unprivileged user can create user and net namespaces
> in which he holds CAP_NET_ADMIN to bypass the netlink_net_capable()
> check:
Applied to nf, thanks.
[...]
> I think xt_osf has the same issue with respect to xt_osf_fingers.
> Also, it looks like nlmon devices created in an unprivileged netns can
> see netlink activity from the init namespace.
A fix that one would be good too.
prev parent reply other threads:[~2017-12-04 10:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-03 20:12 [PATCH] netfilter: nfnetlink_cthelper: Add missing permission checks Kevin Cernekee
2017-12-04 10:32 ` Pablo Neira Ayuso [this message]
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