netdev - Re: [PATCH net] tun: fix return value when the number of iovs exceeds MAX_SKB

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: <CA+FuTSfmKFVZ7_q6nU92YYk-MLKWTa_bkE+L4C8vi5+UQ1_a8A@mail.gmail.com>
Date:   Thu, 24 Dec 2020 10:56:16 -0500
From:   Willem de Bruijn <willemdebruijn.kernel@...il.com>
To:     wangyunjian <wangyunjian@...wei.com>
Cc:     Network Development <netdev@...r.kernel.org>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Jason Wang <jasowang@...hat.com>,
        Willem de Bruijn <willemdebruijn.kernel@...il.com>,
        virtualization@...ts.linux-foundation.org,
        "Lilijun (Jerry)" <jerry.lilijun@...wei.com>,
        chenchanghu <chenchanghu@...wei.com>,
        xudingke <xudingke@...wei.com>,
        "huangbin (J)" <brian.huangbin@...wei.com>
Subject: Re: [PATCH net] tun: fix return value when the number of iovs exceeds MAX_SKB_FRAGS

On Thu, Dec 24, 2020 at 6:51 AM wangyunjian <wangyunjian@...wei.com> wrote:
>
> From: Yunjian Wang <wangyunjian@...wei.com>
>
> Currently the tun_napi_alloc_frags() function returns -ENOMEM when the
> number of iovs exceeds MAX_SKB_FRAGS + 1. However this is inappropriate,
> we should use -EMSGSIZE instead of -ENOMEM.
>
> Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
> Signed-off-by: Yunjian Wang <wangyunjian@...wei.com>

Acked-by: Willem de Bruijn <willemb@...gle.com>

It might be good to explain why the distinction matters: one denotes a
transient failure that the caller (specifically vhost_net) can retry,
the other a persistent failure due to bad packet geometry that should
be dropped.