From: Peter Zijlstra <peterz@infradead.org>
To: Corey Hickey <bugfood-ml@fatooh.org>
Cc: linux-kernel@vger.kernel.org, Dhaval Giani <dhaval@linux.vnet.ibm.com>
Subject: Re: RT scheduling and a way to make a process hang, unkillable
Date: Sun, 15 Feb 2009 12:24:56 +0100 [thread overview]
Message-ID: <1234697096.4713.24.camel@laptop> (raw)
In-Reply-To: <4997672B.1000301@fatooh.org>
On Sat, 2009-02-14 at 16:51 -0800, Corey Hickey wrote:
> Hello,
>
> I've encountered a bit of a problem in recent kernels that include
> "Group scheduling for SCHED_RR/FIFO": it is possible for a process run
> by root to hang itself and become unkillable--even by a 'kill -9'.
>
> The following kernel options must be set:
> CONFIG_GROUP_SCHED=y
> CONFIG_RT_GROUP_SCHED=y
> CONFIG_USER_SCHED=y
>
> The procedure is for a program to:
> 1. run as root
> 2. set SCHED_FIFO
> 3. change UID to a user with no realtime CPU share allocated
Hmm, setuid() should fail in that situation.
/me goes peek at code.
Can't find any code to make that happen, Dhaval didn't we fix that at
one point?
next prev parent reply other threads:[~2009-02-15 11:25 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-15 0:51 RT scheduling and a way to make a process hang, unkillable Corey Hickey
2009-02-15 11:24 ` Peter Zijlstra [this message]
2009-02-16 10:36 ` Dhaval Giani
2009-02-16 11:08 ` Peter Zijlstra
2009-02-16 12:02 ` Dhaval Giani
2009-02-16 12:24 ` Peter Zijlstra
2009-02-16 13:14 ` Dhaval Giani
2009-02-16 13:19 ` Peter Zijlstra
2009-02-16 14:23 ` Peter Zijlstra
2009-02-16 13:20 ` Dhaval Giani
2009-02-16 19:18 ` Corey Hickey
2009-02-17 5:00 ` Dhaval Giani
2009-02-17 10:15 ` Dhaval Giani
2009-02-17 11:15 ` Peter Zijlstra
2009-02-18 0:09 ` Corey Hickey
2009-02-23 11:45 ` Dhaval Giani
2009-02-23 11:59 ` Peter Zijlstra
2009-02-24 9:18 ` Dhaval Giani
2009-02-24 15:58 ` Andi Kleen
2009-02-24 16:36 ` Peter Zijlstra
2009-02-24 19:29 ` Chris Friesen
2009-02-27 9:43 ` [PATCH] sched: Don't allow setuid to succeed if the user does not have rt bandwidth Dhaval Giani
2009-02-27 10:25 ` Ingo Molnar
2009-02-16 20:16 ` RT scheduling and a way to make a process hang, unkillable Kyle Moffett
2009-02-16 20:28 ` Peter Zijlstra
2009-02-17 7:22 ` Dhaval Giani
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