netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Willy Tarreau <w@1wt.eu>
To: Keyu Man <kman001@ucr.edu>
Cc: Eric Dumazet <edumazet@google.com>,
	David Ahern <dsahern@gmail.com>, Florian Westphal <fw@strlen.de>,
	davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
	Jakub Kicinski <kuba@kernel.org>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Zhiyun Qian <zhiyunq@cs.ucr.edu>
Subject: Re: PROBLEM: DoS Attack on Fragment Cache
Date: Sat, 17 Apr 2021 09:50:30 +0200	[thread overview]
Message-ID: <20210417075030.GA14265@1wt.eu> (raw)
In-Reply-To: <CAMqUL6bkp2Dy3AMFZeNLjE1f-sAwnuBWpXH_FSYTSh8=Ac3RKg@mail.gmail.com>

On Sat, Apr 17, 2021 at 12:42:39AM -0700, Keyu Man wrote:
> How about at least allow the existing queue to finish? Currently a tiny new
> fragment would potentially invalid all previous fragments by letting them
> timeout without allowing the fragments to come in to finish the assembly.

Because this is exactly the principle of how attacks are built: reserve
resources claiming that you'll send everything so that others can't make
use of the resources that are reserved to you. The best solution precisely
is *not* to wait for anyone to finish, hence *not* to reserve valuable
resources that are unusuable by others.

Willy

  parent reply	other threads:[~2021-04-17  7:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <02917697-4CE2-4BBE-BF47-31F58BC89025@hxcore.ol>
2021-04-16 23:09 ` PROBLEM: DoS Attack on Fragment Cache Keyu Man
2021-04-17  0:31 ` David Ahern
2021-04-17  4:44   ` Eric Dumazet
2021-04-17  7:27     ` Willy Tarreau
     [not found]       ` <CAMqUL6bkp2Dy3AMFZeNLjE1f-sAwnuBWpXH_FSYTSh8=Ac3RKg@mail.gmail.com>
2021-04-17  7:50         ` Willy Tarreau [this message]
2021-04-18  1:30           ` Matt Corallo
2021-04-18  1:38             ` Keyu Man
2021-04-18  2:26               ` Matt Corallo
2021-04-18  4:39                 ` Willy Tarreau
2021-04-18 14:31                   ` Matt Corallo
2021-04-19  9:43                     ` Eric Dumazet
2021-04-19 17:20                       ` Matt Corallo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210417075030.GA14265@1wt.eu \
    --to=w@1wt.eu \
    --cc=davem@davemloft.net \
    --cc=dsahern@gmail.com \
    --cc=dsahern@kernel.org \
    --cc=edumazet@google.com \
    --cc=fw@strlen.de \
    --cc=kman001@ucr.edu \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=yoshfuji@linux-ipv6.org \
    --cc=zhiyunq@cs.ucr.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).