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Date:   Wed, 5 Apr 2023 12:38:48 -0700
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Subject: Re: [PATCH bpf] xsk: Fix unaligned descriptor validation
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To:     Magnus Karlsson <magnus.karlsson@gmail.com>,
        Kal Conley <kal.conley@dectris.com>
Cc:     =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>,
        Magnus Karlsson <magnus.karlsson@intel.com>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        Jonathan Lemon <jonathan.lemon@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Maxim Mikityanskiy <maximmi@mellanox.com>,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230403143601.32168-1-kal.conley@dectris.com>
 <CAJ8uoz1BKJ1_jq6Sum-OkZQTR_ftmr5Enj+Cmn4Qsi15_jOpbQ@mail.gmail.com>
From:   Martin KaFai Lau <martin.lau@linux.dev>
In-Reply-To: <CAJ8uoz1BKJ1_jq6Sum-OkZQTR_ftmr5Enj+Cmn4Qsi15_jOpbQ@mail.gmail.com>
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On 4/3/23 11:25 PM, Magnus Karlsson wrote:
> On Mon, 3 Apr 2023 at 16:38, Kal Conley <kal.conley@dectris.com> wrote:
>>
>> Make sure unaligned descriptors that straddle the end of the UMEM are
>> considered invalid. Currently, descriptor validation is broken for
>> zero-copy mode which only checks descriptors at page granularity.
>> Descriptors that cross the end of the UMEM but not a page boundary may
>> be therefore incorrectly considered valid. The check needs to happen
>> before the page boundary and contiguity checks in
>> xp_desc_crosses_non_contig_pg. Do this check in
>> xp_unaligned_validate_desc instead like xp_check_unaligned already does.
> 
> Thanks for catching this Kal.
> 
> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>

Is this case covered by an existing test?