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From: Russell King <rmk@arm.linux.org.uk>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjanv@redhat.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: 2.4+ptrace exploit fix breaks root's ability to strace
Date: Sat, 22 Mar 2003 18:01:27 +0000	[thread overview]
Message-ID: <20030322180127.J8712@flint.arm.linux.org.uk> (raw)
In-Reply-To: <1048360147.9221.26.camel@irongate.swansea.linux.org.uk>; from alan@lxorguk.ukuu.org.uk on Sat, Mar 22, 2003 at 07:09:08PM +0000

On Sat, Mar 22, 2003 at 07:09:08PM +0000, Alan Cox wrote:
> On Sat, 2003-03-22 at 17:13, Russell King wrote:
> > ptrace has always explicitly allowed a process with the CAP_SYS_PTRACE
> > capability to ptrace a task which isn't dumpable.  With the ptrace "fix"
> > in place, you can attach to a non-dumpable thread:
> 
> Note that this is a bug, and is now a fixed bug. The looser check you
> can do requires you check
> 
> 	my_capabilities >= his capbilities
> 
> Otherwise you have priviledge escalation for CAP_SYS_PTRACE to
> CAP_SYS_RAWIO trivially

In which case we should not allow ptrace to even attach to the process.
Currently you can attach to such a process and stop it running, even if
you have lesser priviledges than the child.

Therefore, I wouldn't call this "fixed" in the existing ptrace patch.

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html


  reply	other threads:[~2003-03-22 17:50 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-22 10:31 2.4+ptrace exploit fix breaks root's ability to strace Russell King
2003-03-22 14:58 ` Alan Cox
2003-03-22 14:10   ` Russell King
2003-03-22 15:28     ` Arjan van de Ven
2003-03-22 17:13       ` Russell King
2003-03-22 17:28         ` Arjan van de Ven
2003-03-22 19:09         ` Alan Cox
2003-03-22 18:01           ` Russell King [this message]
2003-03-23 10:31   ` Lists (lst)
2003-03-23 10:38     ` Russell King
2003-03-23 11:11       ` Martin Loschwitz
2003-03-23 10:43     ` Arjan van de Ven
2003-04-17  5:46 Yusuf Wilajati Purna
2003-04-19  5:57 ` Bernhard Kaindl
2003-04-22  5:03   ` Yusuf Wilajati Purna

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