From: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
To: John Wood <john.wood@gmx.com>
Cc: kernelnewbies@kernelnewbies.org
Subject: Re: Notify special task kill using wait* functions
Date: Sat, 03 Apr 2021 17:34:01 -0400 [thread overview]
Message-ID: <145687.1617485641@turing-police> (raw)
In-Reply-To: <20210403070226.GA3002@ubuntu>
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On Sat, 03 Apr 2021 09:02:26 +0200, John Wood said:
> Currently, the scenario you propose is fully mitigated :). And notifying to
> userspace that all the tasks has been killed by "Brute" not decrease the
> security. It adds the possibility that the supervisor adopts the correct policy.
So how do you figure out how far up the chain you kill processes?
What does a triple or quadruple fork do? How do you ensure that you deliver
the notification to the correct supervisor? (Hint - walking backwards until you
hit a process running as root isn't necessarily the right answer, especially
once you consider containers and systems where gdm runs as non-root
and other weird stuff..)
Bonus points if you deal correctly with abuse of LD_PRELOAD to front-end
a signal handler that catches SIGSEGV, without breaking the semantics
of legitimate signal handlers...
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next prev parent reply other threads:[~2021-04-03 21:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 17:34 Notify special task kill using wait* functions John Wood
2021-03-30 18:40 ` Valdis Klētnieks
2021-04-02 12:49 ` John Wood
2021-04-03 3:50 ` Valdis Klētnieks
2021-04-03 7:02 ` John Wood
2021-04-03 21:34 ` Valdis Klētnieks [this message]
2021-04-04 9:48 ` John Wood
2021-04-04 21:10 ` Valdis Klētnieks
2021-04-05 7:31 ` John Wood
2021-04-06 23:55 ` Valdis Klētnieks
2021-04-07 17:51 ` John Wood
2021-04-07 20:38 ` Valdis Klētnieks
2021-04-08 1:51 ` Andi Kleen
2021-04-09 14:29 ` John Wood
2021-04-09 15:06 ` Andi Kleen
2021-04-09 16:08 ` John Wood
2021-04-09 23:28 ` Valdis Klētnieks
2021-04-11 8:46 ` John Wood
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