From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
Tom Herbert <tom@herbertland.com>,
Tariq Toukan <ttoukan.linux@gmail.com>,
Tariq Toukan <tariqt@mellanox.com>,
"David S. Miller" <davem@davemloft.net>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
Eran Ben Elisha <eranbe@mellanox.com>,
Saeed Mahameed <saeedm@mellanox.com>,
Rana Shahout <ranas@mellanox.com>,
brouer@redhat.com
Subject: Re: [PATCH net-next 7/8] net/mlx5e: XDP TX forwarding support
Date: Tue, 20 Sep 2016 23:04:30 +0200 [thread overview]
Message-ID: <20160920230430.4756bfc6@redhat.com> (raw)
In-Reply-To: <20160920164526.GB99429@ast-mbp.thefacebook.com>
On Tue, 20 Sep 2016 09:45:28 -0700
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> To your other question:
> > Please explain why a eBPF program error (div by zero) must be a silent drop?
>
> because 'div by zero' is an abnormal situation that shouldn't be exploited.
> Meaning if xdp program is doing DoS prevention and it has a bug that
> attacker can now exploit by sending a crafted packet that causes
> 'div by zero' and kernel will warn then attack got successful.
> Therefore it has to be silent drop.
Understood and documented:
https://github.com/netoptimizer/prototype-kernel/commit/a4e60e2d7a894
Our current solution is not very optimal, it only result in onetime
WARN_ONCE() see bpf_warn_invalid_xdp_action(). But is should not be
affected by the DoS attack scenario you described.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2016-09-20 21:04 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-19 13:58 [PATCH net-next 0/8] mlx5e XDP support Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 1/8] net/mlx5e: Build RX SKB on demand Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 2/8] net/mlx5e: Union RQ RX info per RQ type Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 3/8] net/mlx5e: Slightly reduce hardware LRO size Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 4/8] net/mlx5e: Dynamic RQ type infrastructure Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 5/8] net/mlx5e: XDP fast RX drop bpf programs support Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 6/8] net/mlx5e: Have a clear separation between different SQ types Tariq Toukan
2016-09-19 13:58 ` [PATCH net-next 7/8] net/mlx5e: XDP TX forwarding support Tariq Toukan
2016-09-20 8:29 ` Jesper Dangaard Brouer
2016-09-20 11:33 ` Jesper Dangaard Brouer
2016-09-20 12:53 ` Tariq Toukan
2016-09-20 15:40 ` Alexei Starovoitov
2016-09-20 15:51 ` Tom Herbert
2016-09-20 15:58 ` Eric Dumazet
2016-09-20 16:06 ` Jesper Dangaard Brouer
2016-09-20 16:13 ` Eric Dumazet
2016-09-20 16:27 ` Jesper Dangaard Brouer
2016-09-20 16:45 ` Alexei Starovoitov
2016-09-20 16:58 ` Thomas Graf
2016-09-20 17:39 ` Eric Dumazet
2016-09-20 18:59 ` Jesper Dangaard Brouer
2016-09-20 19:21 ` Tom Herbert
2016-09-20 20:47 ` Jesper Dangaard Brouer
2016-09-20 21:04 ` Jesper Dangaard Brouer [this message]
2016-09-20 16:00 ` Alexei Starovoitov
2016-09-20 15:57 ` Jesper Dangaard Brouer
2016-09-21 7:57 ` Tariq Toukan
2016-09-21 8:16 ` Jesper Dangaard Brouer
2016-09-19 13:58 ` [PATCH net-next 8/8] net/mlx5e: XDP TX xmit more Tariq Toukan
2016-09-20 7:46 ` Jesper Dangaard Brouer
2016-09-20 8:19 ` Tariq Toukan
2016-09-20 9:26 ` Jesper Dangaard Brouer
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