From: John Fastabend <john.fastabend@gmail.com>
To: Jesper Dangaard Brouer <brouer@redhat.com>, sameehj@amazon.com
Cc: "Jesper Dangaard Brouer" <brouer@redhat.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com,
akiyano@amazon.com, gtzalik@amazon.com,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Daniel Borkmann" <borkmann@iogearbox.net>,
"Alexei Starovoitov" <alexei.starovoitov@gmail.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"Alexander Duyck" <alexander.duyck@gmail.com>,
"Jeff Kirsher" <jeffrey.t.kirsher@intel.com>,
"David Ahern" <dsahern@gmail.com>,
"Willem de Bruijn" <willemdebruijn.kernel@gmail.com>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
"Lorenzo Bianconi" <lorenzo@kernel.org>,
"Saeed Mahameed" <saeedm@mellanox.com>,
steffen.klassert@secunet.com
Subject: RE: [PATCH net-next 30/33] xdp: clear grow memory in bpf_xdp_adjust_tail()
Date: Sun, 26 Apr 2020 22:26:54 -0700 [thread overview]
Message-ID: <5ea66d1ec37bc_59462aeb755845b848@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <158757179349.1370371.14581472372520364962.stgit@firesoul>
Jesper Dangaard Brouer wrote:
> Clearing memory of tail when grow happens, because it is too easy
> to write a XDP_PASS program that extend the tail, which expose
> this memory to users that can run tcpdump.
>
> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
> ---
Hi Jesper, Thanks for the series any idea what the cost of doing
this is? If you have some data I would be curious to know a
baseline measurment, a grow with memset, then a grow with memset.
I'm guess this can be relatively expensive?
> net/core/filter.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 5e9c387f74eb..889d96a690c2 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -3442,6 +3442,10 @@ BPF_CALL_2(bpf_xdp_adjust_tail, struct xdp_buff *, xdp, int, offset)
> if (unlikely(data_end < xdp->data + ETH_HLEN))
> return -EINVAL;
>
> + /* Clear memory area on grow, can contain uninit kernel memory */
> + if (offset > 0)
> + memset(xdp->data_end, 0, offset);
> +
> xdp->data_end = data_end;
>
> return 0;
>
>
next prev parent reply other threads:[~2020-04-27 5:27 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <158757160439.1370371.13213378122947426220.stgit@firesoul>
2020-04-22 16:07 ` [PATCH net-next 01/33] xdp: add frame size to xdp_buff Jesper Dangaard Brouer
2020-04-24 14:00 ` Toke Høiland-Jørgensen
2020-04-28 16:06 ` Jesper Dangaard Brouer
2020-04-22 16:07 ` [PATCH net-next 02/33] bnxt: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-22 16:07 ` [PATCH net-next 03/33] sfc: add XDP frame size Jesper Dangaard Brouer
2020-04-22 16:07 ` [PATCH net-next 04/33] mvneta: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-22 16:07 ` [PATCH net-next 05/33] net: netsec: Add support for XDP frame size Jesper Dangaard Brouer
2020-04-22 16:07 ` [PATCH net-next 06/33] net: XDP-generic determining " Jesper Dangaard Brouer
2020-04-24 14:03 ` Toke Høiland-Jørgensen
2020-04-22 16:07 ` [PATCH net-next 07/33] xdp: xdp_frame add member frame_sz and handle in convert_to_xdp_frame Jesper Dangaard Brouer
2020-04-24 14:04 ` Toke Høiland-Jørgensen
2020-04-25 3:24 ` Toshiaki Makita
2020-04-27 15:20 ` Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 08/33] xdp: cpumap redirect use frame_sz and increase skb_tailroom Jesper Dangaard Brouer
2020-04-24 14:04 ` Toke Høiland-Jørgensen
2020-04-22 16:08 ` [PATCH net-next 09/33] veth: adjust hard_start offset on redirect XDP frames Jesper Dangaard Brouer
2020-04-24 14:05 ` Toke Høiland-Jørgensen
2020-04-22 16:08 ` [PATCH net-next 10/33] veth: xdp using frame_sz in veth driver Jesper Dangaard Brouer
2020-04-24 14:07 ` Toke Høiland-Jørgensen
2020-04-25 3:10 ` Toshiaki Makita
2020-04-22 16:08 ` [PATCH net-next 11/33] dpaa2-eth: add XDP frame size Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 12/33] hv_netvsc: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-22 16:57 ` Haiyang Zhang
2020-04-22 16:08 ` [PATCH net-next 13/33] qlogic/qede: " Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 14/33] net: ethernet: ti: add XDP frame size to driver cpsw Jesper Dangaard Brouer
2020-04-22 20:28 ` Grygorii Strashko
2020-04-22 16:08 ` [PATCH net-next 15/33] ena: add XDP frame size to amazon NIC driver Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 16/33] mlx4: add XDP frame size and adjust max XDP MTU Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 17/33] net: thunderx: add XDP frame size Jesper Dangaard Brouer
2020-04-22 16:08 ` [PATCH net-next 18/33] nfp: add XDP frame size to netronome driver Jesper Dangaard Brouer
2020-04-23 2:43 ` Jakub Kicinski
2020-04-22 16:08 ` [PATCH net-next 19/33] tun: add XDP frame size Jesper Dangaard Brouer
2020-04-27 5:51 ` Jason Wang
2020-05-06 20:30 ` Michael S. Tsirkin
2020-04-22 16:09 ` [PATCH net-next 20/33] vhost_net: also populate " Jesper Dangaard Brouer
2020-04-27 5:50 ` Jason Wang
2020-04-30 9:54 ` Jesper Dangaard Brouer
2020-05-06 6:43 ` Jason Wang
2020-04-22 16:09 ` [PATCH net-next 21/33] virtio_net: add XDP frame size in two code paths Jesper Dangaard Brouer
2020-04-27 7:21 ` Jason Wang
2020-04-27 14:32 ` Jesper Dangaard Brouer
2020-04-28 9:50 ` Jason Wang
2020-04-30 10:14 ` Jesper Dangaard Brouer
2020-05-06 6:38 ` Jason Wang
2020-04-22 16:09 ` [PATCH net-next 22/33] ixgbe: fix XDP redirect on archs with PAGE_SIZE above 4K Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 23/33] ixgbe: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-27 19:51 ` Daniel Borkmann
2020-04-22 16:09 ` [PATCH net-next 24/33] ixgbevf: add XDP frame size to VF driver Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 25/33] i40e: add XDP frame size to driver Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 26/33] ice: " Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 27/33] xdp: for Intel AF_XDP drivers add XDP frame_sz Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 28/33] mlx5: rx queue setup time determine frame_sz for XDP Jesper Dangaard Brouer
2020-04-25 0:58 ` Alexei Starovoitov
2020-04-27 20:22 ` Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 29/33] xdp: allow bpf_xdp_adjust_tail() to grow packet size Jesper Dangaard Brouer
2020-04-24 14:09 ` Toke Høiland-Jørgensen
2020-04-27 19:01 ` Daniel Borkmann
2020-04-28 16:37 ` Jesper Dangaard Brouer
2020-04-28 19:36 ` Daniel Borkmann
2020-04-22 16:09 ` [PATCH net-next 30/33] xdp: clear grow memory in bpf_xdp_adjust_tail() Jesper Dangaard Brouer
2020-04-24 14:09 ` Toke Høiland-Jørgensen
2020-04-27 5:26 ` John Fastabend [this message]
2020-04-28 14:50 ` Jesper Dangaard Brouer
2020-04-22 16:09 ` [PATCH net-next 31/33] bpf: add xdp.frame_sz in bpf_prog_test_run_xdp() Jesper Dangaard Brouer
2020-04-22 16:10 ` [PATCH net-next 32/33] selftests/bpf: adjust BPF selftest for xdp_adjust_tail Jesper Dangaard Brouer
2020-04-22 16:10 ` [PATCH net-next 33/33] selftests/bpf: xdp_adjust_tail add grow tail tests Jesper Dangaard Brouer
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