From: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
To: John Wood <john.wood@gmx.com>
Cc: kernelnewbies@kernelnewbies.org
Subject: Re: Read the "real_parent" field of task_struct
Date: Thu, 01 Oct 2020 20:29:58 -0400 [thread overview]
Message-ID: <187490.1601598598@turing-police> (raw)
In-Reply-To: <20201001174902.GA3046@ubuntu>
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On Thu, 01 Oct 2020 19:49:02 +0200, John Wood said:
> Idea: The purpose of my LSM is to detect and mitigate a fork brute force
> attack. To do so, I need a hierarchy of fork processes. In other words, there
> is a pointer in the task_struct structure that points to an statistics data
> structure. This pointer is copied to the child process when a process forks.
> This way, all the tasks that fork with the same root share the same statistics.
> These statistics allow to compute the application crashing period and detect
> the attack.
How is this any better than applying a ulimit to the userid, and using the existing
audit subsystem for reporting the attack, which is what that subsystem was
designed for?
> But there is the case when the task 0 is allocated. In this case it's not
> possible to copy the parent pointer to the statistical data. The task 0 don't
> have parent. In this scenario a new statistics structure need to be allocated.
At that point, your LSM probably hasn't been initialized yet. If your LSM is being
called before task 0 (let alone task 1) is created, there's probably something
wonky going on. Are you seeing this happen on an actual system?
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next prev parent reply other threads:[~2020-10-02 0:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 16:11 Read the "real_parent" field of task_struct John Wood
2020-09-30 11:59 ` Valdis Klētnieks
2020-10-01 17:49 ` John Wood
2020-10-02 0:29 ` Valdis Klētnieks [this message]
2020-10-02 16:59 ` John Wood
2020-10-08 17:05 ` John Wood
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