netdev - Re: [PATCH net-next] net: tso: double TSO_HEADER

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] [day] [month] [year] [list]

Date:   Wed, 17 Jun 2020 10:20:48 -0700
From:   Eric Dumazet <edumazet@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Eric Dumazet <eric.dumazet@...il.com>,
        Antoine Tenart <antoine.tenart@...tlin.com>
Subject: Re: [PATCH net-next] net: tso: double TSO_HEADER_SIZE value

On Wed, Jun 17, 2020 at 10:19 AM Eric Dumazet <edumazet@...gle.com> wrote:
>
> Transport header size could be 60 bytes, and network header
> size can also be 60 bytes. Add the Ethernet header and we
> are above 128 bytes.
>
> Since drivers using net/core/tso.c usually allocates
> one DMA coherent piece of memory per RX queue, this patch
                                                  typo here : TX queue

>
> might cause issues if a driver was using too many slots.
>
> For 1024 slots, we would need 256 KB of physically
> contiguous memory instead of 128 KB.
>
> Alternative fix would be to add checks in the fast path,
> but this involves more work in all drivers using net/core/tso.c.
>
> Fixes: f9cbe9a556af ("net: define the TSO header size in net/tso.h")
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Cc: Antoine Tenart <antoine.tenart@...tlin.com>
> ---
> Note: probably needs to stay in net-next for one release cycle.
>
>  include/net/tso.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/tso.h b/include/net/tso.h
> index 7e166a5703497fadf4662acc474f827b2754da78..c33dd00c161f7a6aa65f586b0ceede46af2e8730 100644
> --- a/include/net/tso.h
> +++ b/include/net/tso.h
> @@ -4,7 +4,7 @@
>
>  #include <net/ip.h>
>
> -#define TSO_HEADER_SIZE                128
> +#define TSO_HEADER_SIZE                256
>
>  struct tso_t {
>         int next_frag_idx;
> --
> 2.27.0.290.gba653c62da-goog
>