netdev - Re: [PATCH] gro: check returned skb of napi_frags

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]

Message-ID: <CANn89iKxGVDQba1UCbpYKhNo=rZXuN2j=610DbJx0z=kWa7N3w@mail.gmail.com>
Date: Thu, 6 Jul 2023 15:52:50 +0200
From: Eric Dumazet <edumazet@...gle.com>
To: Kaiyu Zhang <squirrel.prog@...il.com>
Cc: davem@...emloft.net, kuba@...nel.org, pabeni@...hat.com, 
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] gro: check returned skb of napi_frags_skb() against NULL

On Thu, Jul 6, 2023 at 3:08 PM Kaiyu Zhang <squirrel.prog@...il.com> wrote:
>
> Some rogue network adapter and their driver pass bad skbs to GRO.
> napi_frags_skb() detects this, drops these bad skbs, and return NULL
> to napi_gro_frags(), which does not check returned skb against NULL
> and access it. This results in a kernel crash.
>
> A better approach to address these bad skbs would be to issue some
> warnings and drop them, which napi_frags_skb() already does, and
> move on without crashing the kernel.
>

Certainly not.

We are not going to try to be nice to buggy drivers.

Please fix the "rogue network adapter" instead.