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: xt_osf: Add missing permission checks
Date: Wed, 6 Dec 2017 09:01:34 +0100 [thread overview]
Message-ID: <20171206080134.GA2844@salvia> (raw)
In-Reply-To: <1512517361-23689-1-git-send-email-cernekee@chromium.org>
On Tue, Dec 05, 2017 at 03:42:41PM -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, xt_osf_fingers is shared by all net namespaces on the
> system. An unprivileged user can create user and net namespaces
> in which he holds CAP_NET_ADMIN to bypass the netlink_net_capable()
> check:
>
> vpnns -- nfnl_osf -f /tmp/pf.os
>
> vpnns -- nfnl_osf -f /tmp/pf.os -d
>
> These non-root operations successfully modify the systemwide OS
> fingerprint list. Add new capable() checks so that they can't.
Applied, thanks Kevin.
prev parent reply other threads:[~2017-12-06 8:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-05 23:42 [PATCH] netfilter: xt_osf: Add missing permission checks Kevin Cernekee
2017-12-06 8:01 ` Pablo Neira Ayuso [this message]
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