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From: John Wood <john.wood@gmx.com>
To: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
Cc: John Wood <john.wood@gmx.com>, kernelnewbies@kernelnewbies.org
Subject: Re: Notify special task kill using wait* functions
Date: Mon, 5 Apr 2021 09:31:47 +0200	[thread overview]
Message-ID: <20210405073147.GA3053@ubuntu> (raw)
In-Reply-To: <193167.1617570625@turing-police>

Hi,

On Sun, Apr 04, 2021 at 05:10:25PM -0400, Valdis Klētnieks wrote:
> On Sun, 04 Apr 2021 11:48:37 +0200, John Wood said:
>
> > that exec and the child crashes is mitigated. The only drawback here, as
> > point Andi, is that a supervisor respawns some process killed. To avoid
> > this situation he suggest to notify to usersapace via wait* that the
> > task has been killed by "brute". Then, this supervisor has the chance to
> > do what they need (respawn or not).
>
> And how does the kernel know that it's notifying a "real" supervisor process,
> and not a process started by the bad guy, who can receive the notification
> and decide to respawn?
>
Well, I think this is not possible to know. Anyway, I believe that the "bad
guy" not rely on the wait* notification to decide to respawn or not. He
will do the attack without waiting any notification.

Anyway thanks a lot for this new point of view.

Thanks,
John Wood

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  reply	other threads:[~2021-04-05  7:32 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30 17:34 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
2021-04-04  9:48           ` John Wood
2021-04-04 21:10             ` Valdis Klētnieks
2021-04-05  7:31               ` John Wood [this message]
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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