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From: John Wood <john.wood@gmx.com>
To: Jeffrey Walton <noloader@gmail.com>,
	kernelnewbies <kernelnewbies@kernelnewbies.org>
Cc: John Wood <john.wood@gmx.com>
Subject: Re: Test if a socket accept is from external network
Date: Sun, 25 Apr 2021 15:34:30 +0200	[thread overview]
Message-ID: <20210425133430.GA3407@ubuntu> (raw)
In-Reply-To: <CAH8yC8kiud9BK89i0R4ycQ2QTddC_pWi+vRp6sGUcxiOJuoLZw@mail.gmail.com>

Hi,

On Sun, Apr 25, 2021 at 08:01:55AM -0400, Jeffrey Walton wrote:
> On Sun, Apr 25, 2021 at 7:09 AM John Wood <john.wood@gmx.com> wrote:
> >
> > I'm working in a LSM to detect and mitigate fork brute force attacks
> > against vulnerable userspace applications. Now, to fine tuning the
> > detection I want to detect a network activity.  ...
> > How can I detect that an external connection (using a net device) is
> > accepted and avoid internal network communication?
>
> One caveat that may (or may not) apply...
>
> Systemd opens sockets for services even when a service is disabled. It
> could appear that a system is accepting traffic even when the service
> is unavailable.

But if the service is unavailable it will not accept connections. I hope.
If we use the socket_accept LSM hook it will not be called under this
scenario.

John Wood

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  reply	other threads:[~2021-04-25 13:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-25 11:08 Test if a socket accept is from external network John Wood
2021-04-25 12:01 ` Jeffrey Walton
2021-04-25 13:34   ` John Wood [this message]
2021-05-05  1:39   ` jim.cromie

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