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Date:   Thu, 31 Aug 2023 00:59:21 +0200
From:   Florian Westphal <fw@strlen.de>
To:     Wander Lairson Costa <wander@redhat.com>
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "open list:NETFILTER" <netfilter-devel@vger.kernel.org>,
        "open list:NETFILTER" <coreteam@netfilter.org>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Lucas Leong <wmliang@infosec.exchange>, stable@kernel.org
Subject: Re: [PATCH nf] netfilter/osf: avoid OOB read
Message-ID: <20230830225921.GA15759@breakpoint.cc>
References: <20230830205554.97083-2-wander@redhat.com>
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Wander Lairson Costa <wander@redhat.com> wrote:
> The opt_num field is controlled by user mode and is not currently
> validated inside the kernel. An attacker can take advantage of this to
> trigger an OOB read and potentially leak information.

[..]

Can you send a v2 that rejects bogus nf_osf_user_finger structs?

nfnl_osf_add_callback() seems to be the right place to refuse it.