From: Jamie Lokier <jamie@shareable.org>
To: Ulrich Drepper <drepper@redhat.com>
Cc: Andrea Arcangeli <andrea@suse.de>,
john stultz <johnstul@us.ibm.com>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH] linux-2.6.2-rc2_vsyscall-gtod_B1.patch
Date: Tue, 3 Feb 2004 08:52:24 +0000 [thread overview]
Message-ID: <20040203085224.GA15738@mail.shareable.org> (raw)
In-Reply-To: <401F251C.2090300@redhat.com>
Ulrich Drepper wrote:
> You got to be kidding. Some object fixed in the address space which can
> perform system calls. Nothing is more welcome to somebody trying to
> exploit some bugs.
Two approaches to randomising the vdso address:
1. Selecting a random address at boot time. All tasks have the same
vdso for that run of the kernel. Advantages: no MSR write at
each context switch; could patch libsyscall.so at boot time with
address if we were fanatical about optimisation (i.e. other
libcs, not Glibc :) Disadvantages: the attacker may eventually
learn the address.
2. Select a random address for every new task. Advantages: harder
to guess from studying a machine for a long time. Disadvantages:
slower context switches; the gain from randomising each task is
nothing if all the tasks are very long lived anyway.
-- Jamie
next prev parent reply other threads:[~2004-02-03 8:52 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-29 2:46 [RFC][PATCH] linux-2.6.2-rc2_vsyscall-gtod_B1.patch john stultz
2004-01-29 5:06 ` Ulrich Drepper
2004-01-29 13:26 ` Jamie Lokier
2004-01-29 18:05 ` Ulrich Drepper
2004-01-29 19:15 ` Jamie Lokier
2004-01-29 23:59 ` john stultz
2004-01-30 0:40 ` Ulrich Drepper
2004-01-30 0:31 ` Ulrich Drepper
2004-01-30 4:17 ` Jamie Lokier
2004-01-30 5:09 ` Ulrich Drepper
2004-01-30 9:29 ` Ingo Molnar
2004-02-03 4:38 ` Ulrich Drepper
2004-01-30 17:34 ` Jamie Lokier
2004-01-30 8:33 ` Jakub Jelinek
2004-01-30 17:21 ` Jamie Lokier
2004-01-31 0:10 ` Eric W. Biederman
2004-01-31 2:41 ` Jamie Lokier
2004-01-31 5:54 ` Eric W. Biederman
2004-02-01 1:28 ` Andrea Arcangeli
2004-02-03 4:35 ` Ulrich Drepper
2004-02-03 5:34 ` Andrea Arcangeli
2004-02-03 8:52 ` Jamie Lokier [this message]
2004-02-03 16:25 ` Andrea Arcangeli
2004-02-03 17:37 ` Jamie Lokier
2004-02-03 18:10 ` Andrea Arcangeli
2004-02-03 18:23 ` Jamie Lokier
2004-02-03 18:34 ` Andrea Arcangeli
2004-01-31 0:17 ` Eric W. Biederman
2004-01-31 2:20 ` john stultz
[not found] <1075344395.1592.87.camel@cog.beaverton.ibm.com.suse.lists.linux.kernel>
[not found] ` <401894DA.7000609@redhat.com.suse.lists.linux.kernel>
[not found] ` <20040201012803.GN26076@dualathlon.random.suse.lists.linux.kernel>
[not found] ` <401F251C.2090300@redhat.com.suse.lists.linux.kernel>
[not found] ` <20040203085224.GA15738@mail.shareable.org.suse.lists.linux.kernel>
[not found] ` <20040203162515.GY26076@dualathlon.random.suse.lists.linux.kernel>
[not found] ` <20040203173716.GC17895@mail.shareable.org.suse.lists.linux.kernel>
[not found] ` <20040203181001.GA26076@dualathlon.random.suse.lists.linux.kernel>
[not found] ` <20040203182310.GA18326@mail.shareable.org.suse.lists.linux.kernel>
2004-02-04 2:27 ` Andi Kleen
2004-02-04 2:40 ` Andrea Arcangeli
2004-02-04 4:21 ` Jamie Lokier
2004-02-05 21:43 ` Andrea Arcangeli
2004-02-06 4:15 ` Rik van Riel
2004-02-06 4:28 ` Andrea Arcangeli
2004-02-06 9:23 ` Ulrich Drepper
2004-02-06 15:49 ` Andrea Arcangeli
2004-02-07 0:37 ` Ulrich Drepper
2004-02-07 2:19 ` Andrea Arcangeli
2004-02-07 3:37 ` Daniel Jacobowitz
2004-02-07 4:36 ` Andrea Arcangeli
2004-02-07 4:53 ` Jamie Lokier
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