netdev - Re: [PATCH net] virtio-net: reject small vring sizes

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: <20230423070705-mutt-send-email-mst@kernel.org>
Date:   Sun, 23 Apr 2023 07:08:25 -0400
From:   "Michael S. Tsirkin" <mst@...hat.com>
To:     Alvaro Karsz <alvaro.karsz@...id-run.com>
Cc:     Jason Wang <jasowang@...hat.com>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "edumazet@...gle.com" <edumazet@...gle.com>,
        "kuba@...nel.org" <kuba@...nel.org>,
        "pabeni@...hat.com" <pabeni@...hat.com>,
        "virtualization@...ts.linux-foundation.org" 
        <virtualization@...ts.linux-foundation.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net] virtio-net: reject small vring sizes

On Sun, Apr 23, 2023 at 08:01:35AM +0000, Alvaro Karsz wrote:
> We could add a new virtio_config_ops: peek_vqs.
> We can call it during virtnet_validate, and then fixup the features in case of small vrings.
> 
> If peek_vqs is not implemented by the transport, we can just fail probe later in case of small vrings.
> 

Nope, we can't. Driver is not supposed to discover vqs before
FEATURES_OK, the vq size might depend on features.