netdev - Re: [PATCH v5 bpf 07/11] intel: xsk: initialize skb_frag_t::bv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJ8uoz2d-ybdO5P54jmjVgfzH-qODuSAPcToFGqJ+fQo4Sc5JQ@mail.gmail.com>
Date: Wed, 24 Jan 2024 09:44:03 +0100
From: Magnus Karlsson <magnus.karlsson@...il.com>
To: Maciej Fijalkowski <maciej.fijalkowski@...el.com>
Cc: bpf@...r.kernel.org, ast@...nel.org, daniel@...earbox.net, 
	andrii@...nel.org, netdev@...r.kernel.org, magnus.karlsson@...el.com, 
	bjorn@...nel.org, echaudro@...hat.com, lorenzo@...nel.org, 
	martin.lau@...ux.dev, tirthendu.sarkar@...el.com, john.fastabend@...il.com, 
	horms@...nel.org
Subject: Re: [PATCH v5 bpf 07/11] intel: xsk: initialize skb_frag_t::bv_offset
 in ZC drivers

On Mon, 22 Jan 2024 at 23:17, Maciej Fijalkowski
<maciej.fijalkowski@...el.com> wrote:
>
> Ice and i40e ZC drivers currently set offset of a frag within
> skb_shared_info to 0, wchih is incorrect. xdp_buffs that come from

Is "wchih" Polish? Just kidding with you ;-)!

> xsk_buff_pool always have 256 bytes of a headroom, so they need to be
> taken into account to retrieve xdp_buff::data via skb_frag_address().
> Otherwise, bpf_xdp_frags_increase_tail() would be starting its job from
> xdp_buff::data_hard_start which would result in overwriting existing
> payload.

Acked-by: Magnus Karlsson <magnus.karlsson@...el.com>

> Fixes: 1c9ba9c14658 ("i40e: xsk: add RX multi-buffer support")
> Fixes: 1bbc04de607b ("ice: xsk: add RX multi-buffer support")
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@...el.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_xsk.c | 3 ++-
>  drivers/net/ethernet/intel/ice/ice_xsk.c   | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> index fede0bb3e047..65f38a57b3df 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> @@ -414,7 +414,8 @@ i40e_add_xsk_frag(struct i40e_ring *rx_ring, struct xdp_buff *first,
>         }
>
>         __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
> -                                  virt_to_page(xdp->data_hard_start), 0, size);
> +                                  virt_to_page(xdp->data_hard_start),
> +                                  XDP_PACKET_HEADROOM, size);
>         sinfo->xdp_frags_size += size;
>         xsk_buff_add_frag(xdp);
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index d9073a618ad6..8b81a1677045 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -825,7 +825,8 @@ ice_add_xsk_frag(struct ice_rx_ring *rx_ring, struct xdp_buff *first,
>         }
>
>         __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
> -                                  virt_to_page(xdp->data_hard_start), 0, size);
> +                                  virt_to_page(xdp->data_hard_start),
> +                                  XDP_PACKET_HEADROOM, size);
>         sinfo->xdp_frags_size += size;
>         xsk_buff_add_frag(xdp);
>
> --
> 2.34.1
>
>