From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kees Cook <kees.cook@canonical.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Will Drewry <wad@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering
Date: Sun, 29 May 2011 10:02:06 -0700 [thread overview]
Message-ID: <BANLkTimuixiwGS0VkWBiB63pzMov8ZB62Q@mail.gmail.com> (raw)
In-Reply-To: <8762otqwke.fsf@linux.vnet.ibm.com>
On Sun, May 29, 2011 at 9:51 AM, Aneesh Kumar K.V
<aneesh.kumar@linux.vnet.ibm.com> wrote:
>
> The "make sure we don't follow symlinks at all" is a real problem in
> VirtFS (http://wiki.qemu.org/Documentation/9psetup) that we are fixing
> by adding a forked chrooted process to Qemu. If we are open to a new
> open flag O_NOFOLLOW_PATH, which would fail with ELOOP if any of the
> path component is a symbolic link, that would greatly simplify VirtFS.
> Will such a new flag to open be acceptable ?
Such a flag should be something like 3 lines of actual code (and then
the header file changes to actually add the mask itself, which is apt
to be th ebulk of the patch just because we have to have different
values for different architectures).
And yes, it is absolutely acceptable. The only questions in my mind are
- why haven't we done this long ago?
- do we have the flag space?
- should we do a O_NOMNT_PATH flag to do the same for mount-points?
Some people worry about being confused by bind mounts etc.
- do we think ".." is worthy of a flag too?
or is that a "user space can damn well check that itself, even if
it would be absolutely trivial to check in the kernel too"?
Whatever. I think the NOFOLLOW_PATH one is pretty much a no-brainer.
It's not like symlink worries are unusual.
Linus
next prev parent reply other threads:[~2011-05-29 17:03 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1305563026.5456.19.camel@gandalf.stny.rr.com>
[not found] ` <20110516165249.GB10929@elte.hu>
[not found] ` <1305565422.5456.21.camel@gandalf.stny.rr.com>
[not found] ` <20110517124212.GB21441@elte.hu>
[not found] ` <1305637528.5456.723.camel@gandalf.stny.rr.com>
[not found] ` <20110517131902.GF21441@elte.hu>
[not found] ` <BANLkTikBK3-KZ10eErQ6Eex_L6Qe2aZang@mail.gmail.com>
[not found] ` <1305807728.11267.25.camel@gandalf.stny.rr.com>
[not found] ` <BANLkTiki8aQJbFkKOFC+s6xAEiuVyMM5MQ@mail.gmail.com>
[not found] ` <BANLkTim9UyYAGhg06vCFLxkYPX18cPymEQ@mail.gmail.com>
[not found] ` <20110524200815.GD27634@elte.hu>
2011-05-24 20:25 ` Kees Cook
2011-05-25 19:09 ` Ingo Molnar
2011-05-25 16:40 ` Will Drewry
[not found] ` <1306254027.18455.47.camel@twins>
[not found] ` <20110524195435.GC27634@elte.hu>
[not found] ` <alpine.LFD.2.02.1105242239230.3078@ionos>
[not found] ` <20110525150153.GE29179@elte.hu>
[not found] ` <alpine.LFD.2.02.1105251836030.3078@ionos>
2011-05-25 18:01 ` Kees Cook
2011-05-25 18:42 ` Linus Torvalds
2011-05-25 19:06 ` Ingo Molnar
2011-05-25 19:54 ` Will Drewry
2011-05-25 19:11 ` Kees Cook
2011-05-25 20:01 ` Linus Torvalds
2011-05-25 20:19 ` Ingo Molnar
2011-06-09 9:00 ` Sven Anders
2011-05-26 14:37 ` Colin Walters
2011-05-26 15:03 ` Linus Torvalds
2011-05-26 15:28 ` Colin Walters
2011-05-26 16:33 ` Will Drewry
2011-05-26 16:46 ` Linus Torvalds
2011-05-26 17:02 ` Will Drewry
2011-05-26 17:04 ` Will Drewry
2011-05-26 17:17 ` Linus Torvalds
2011-05-26 17:38 ` Will Drewry
2011-05-26 18:33 ` Linus Torvalds
2011-05-26 18:47 ` Ingo Molnar
2011-05-26 19:05 ` david
2011-05-26 19:09 ` Eric Paris
2011-05-26 19:46 ` Ingo Molnar
2011-05-26 19:49 ` david
2011-05-26 18:49 ` Will Drewry
2011-06-01 3:10 ` [PATCH v3 01/13] tracing: split out filter initialization and clean up Will Drewry
2011-06-01 3:10 ` [PATCH v3 02/13] tracing: split out syscall_trace_enter construction Will Drewry
2011-06-01 7:00 ` Ingo Molnar
2011-06-01 17:15 ` Will Drewry
2011-06-02 14:29 ` Ingo Molnar
2011-06-02 15:18 ` Will Drewry
2011-06-01 3:10 ` [PATCH v3 03/13] seccomp_filters: new mode with configurable syscall filters Will Drewry
2011-06-02 17:36 ` Paul E. McKenney
2011-06-02 18:14 ` Will Drewry
2011-06-02 19:42 ` Paul E. McKenney
2011-06-02 20:28 ` Will Drewry
2011-06-02 20:46 ` Steven Rostedt
2011-06-02 21:12 ` Paul E. McKenney
2011-06-01 3:10 ` [PATCH v3 04/13] seccomp_filter: add process state reporting Will Drewry
2011-06-01 3:10 ` [PATCH v3 05/13] seccomp_filter: Document what seccomp_filter is and how it works Will Drewry
2011-06-01 21:23 ` Kees Cook
2011-06-01 23:03 ` Will Drewry
2011-06-01 3:10 ` [PATCH v3 06/13] x86: add HAVE_SECCOMP_FILTER and seccomp_execve Will Drewry
2011-06-01 3:10 ` [PATCH v3 07/13] arm: select HAVE_SECCOMP_FILTER Will Drewry
2011-06-01 3:10 ` [PATCH v3 08/13] microblaze: select HAVE_SECCOMP_FILTER and provide seccomp_execve Will Drewry
2011-06-01 5:37 ` Michal Simek
2011-06-01 3:10 ` [PATCH v3 09/13] mips: " Will Drewry
2011-06-01 3:10 ` [PATCH v3 10/13] s390: " Will Drewry
2011-06-01 3:10 ` [PATCH v3 11/13] powerpc: " Will Drewry
2011-06-01 3:10 ` [PATCH v3 12/13] sparc: " Will Drewry
2011-06-01 3:35 ` David Miller
2011-06-01 3:10 ` [PATCH v3 13/13] sh: select HAVE_SECCOMP_FILTER Will Drewry
2011-06-02 5:27 ` Paul Mundt
2011-05-26 17:38 ` [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering Valdis.Kletnieks
2011-05-26 18:08 ` Will Drewry
2011-05-26 18:22 ` Valdis.Kletnieks
2011-05-26 17:07 ` Steven Rostedt
2011-05-26 18:43 ` Casey Schaufler
2011-05-26 18:54 ` Steven Rostedt
2011-05-26 18:34 ` david
2011-05-26 18:54 ` Ingo Molnar
2011-05-26 1:19 ` James Morris
2011-05-26 6:08 ` Avi Kivity
2011-05-26 8:24 ` Ingo Molnar
2011-05-26 8:35 ` Pekka Enberg
2011-05-26 8:49 ` Avi Kivity
2011-05-26 8:57 ` Pekka Enberg
[not found] ` <20110526085939.GG29458@redhat.com>
2011-05-26 10:38 ` Ingo Molnar
2011-05-26 10:46 ` Avi Kivity
2011-05-26 10:46 ` Gleb Natapov
2011-05-26 11:11 ` Ingo Molnar
2011-05-26 9:30 ` Ingo Molnar
2011-05-26 9:48 ` Ingo Molnar
2011-05-26 11:02 ` Avi Kivity
2011-05-26 11:16 ` Ingo Molnar
2011-05-26 10:56 ` Avi Kivity
2011-05-26 11:38 ` Ingo Molnar
2011-05-26 18:06 ` Avi Kivity
2011-05-26 18:15 ` Ingo Molnar
2011-05-26 18:20 ` Avi Kivity
2011-05-26 18:36 ` Ingo Molnar
2011-05-26 18:43 ` Valdis.Kletnieks
2011-05-26 18:50 ` Ingo Molnar
2011-05-26 18:22 ` Peter Zijlstra
2011-05-26 18:38 ` Ingo Molnar
2011-05-27 0:12 ` James Morris
2011-05-29 16:51 ` Aneesh Kumar K.V
2011-05-29 17:02 ` Linus Torvalds [this message]
2011-05-29 18:23 ` Al Viro
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