From: Tejun Heo <tj@kernel.org>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
containers@lists.osdl.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, Nathan Lynch <ntl@pobox.com>,
kernel-hardening@lists.openwall.com,
Oren Laadan <orenl@cs.columbia.edu>,
Daniel Lezcano <dlezcano@fr.ibm.com>,
Glauber Costa <glommer@parallels.com>,
James Bottomley <jbottomley@parallels.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/ directory v6
Date: Wed, 7 Sep 2011 01:51:44 +0900 [thread overview]
Message-ID: <20110906165144.GJ18425@mtj.dyndns.org> (raw)
In-Reply-To: <20110906101518.GA4799@albatros>
Hello, Vasiliy.
On Tue, Sep 06, 2011 at 02:15:18PM +0400, Vasiliy Kulikov wrote:
> c) If dentry is lazily dropped on each access attempt (or each illegal
> access) then PID2 can:
>
> i) read dentry line of /proc/slabinfo
> ii) call link(2) against /proc/PID/fd, which invalidates the
> specific dentry
> iii) re-read dentry line of /proc/slabinfo. If it has decreased by
> one, the dentry existed before (ii).
If we really worry about this, probably the right thing to do is
hiding slabinfo from mortal UIDs instead of worrying about what
exactly are freed or not from each user.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-09-06 16:52 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-31 7:58 [patch 0/2] Introduce /proc/pid/map_files v6 Cyrill Gorcunov
2011-08-31 7:58 ` [patch 1/2] fs, proc: Make proc_get_link to use dentry instead of inode Cyrill Gorcunov
2011-08-31 7:58 ` [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/ directory v6 Cyrill Gorcunov
2011-08-31 9:06 ` Vasiliy Kulikov
2011-08-31 10:12 ` Cyrill Gorcunov
2011-08-31 11:26 ` Cyrill Gorcunov
2011-08-31 14:04 ` Kirill A. Shutemov
2011-08-31 14:09 ` Cyrill Gorcunov
2011-08-31 14:26 ` Cyrill Gorcunov
2011-08-31 22:10 ` Andrew Morton
2011-09-01 3:07 ` Kyle Moffett
2011-09-01 7:58 ` Pavel Emelyanov
2011-09-01 11:50 ` Tejun Heo
2011-09-01 12:13 ` Pavel Emelyanov
2011-09-01 17:13 ` Tejun Heo
2011-09-02 19:15 ` Matt Helsley
2011-09-02 0:09 ` Matt Helsley
2011-09-01 8:05 ` Cyrill Gorcunov
2011-09-02 16:37 ` Vasiliy Kulikov
2011-09-05 18:53 ` Vasiliy Kulikov
2011-09-05 19:20 ` Cyrill Gorcunov
2011-09-05 19:49 ` Vasiliy Kulikov
2011-09-05 20:36 ` Cyrill Gorcunov
2011-09-06 10:15 ` Vasiliy Kulikov
2011-09-06 16:51 ` Tejun Heo [this message]
2011-09-06 17:29 ` Vasiliy Kulikov
2011-09-06 17:33 ` Tejun Heo
2011-09-06 18:15 ` Cyrill Gorcunov
[not found] ` <20110907112301.GA12157@albatros>
2011-09-07 21:53 ` Cyrill Gorcunov
2011-09-07 22:13 ` Andrew Morton
2011-09-07 22:42 ` Cyrill Gorcunov
2011-09-07 22:53 ` Andrew Morton
2011-09-08 5:48 ` Cyrill Gorcunov
2011-09-08 5:50 ` Cyrill Gorcunov
2011-09-08 6:04 ` Cyrill Gorcunov
2011-09-08 23:52 ` Andrew Morton
2011-09-09 0:24 ` Pavel Emelyanov
2011-09-09 5:48 ` Cyrill Gorcunov
2011-09-09 6:00 ` Andrew Morton
2011-09-09 6:22 ` Cyrill Gorcunov
2011-09-10 13:21 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-10 13:49 ` Cyrill Gorcunov
2011-09-01 10:46 ` Cyrill Gorcunov
2011-09-01 22:49 ` Andrew Morton
2011-09-01 23:04 ` Tejun Heo
2011-09-02 5:54 ` Cyrill Gorcunov
2011-09-02 5:53 ` Cyrill Gorcunov
2011-08-31 22:50 ` Andrew Morton
2011-09-02 1:54 ` Nicholas Miell
2011-09-02 1:58 ` Tejun Heo
2011-09-02 2:04 ` Nicholas Miell
2011-09-02 2:29 ` Tejun Heo
2011-09-02 8:07 ` Kirill A. Shutemov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110906165144.GJ18425@mtj.dyndns.org \
--to=tj@kernel.org \
--cc=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=containers@lists.osdl.org \
--cc=dlezcano@fr.ibm.com \
--cc=glommer@parallels.com \
--cc=gorcunov@gmail.com \
--cc=jbottomley@parallels.com \
--cc=kernel-hardening@lists.openwall.com \
--cc=kirill@shutemov.name \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ntl@pobox.com \
--cc=orenl@cs.columbia.edu \
--cc=segoon@openwall.com \
--cc=viro@ZenIV.linux.org.uk \
--cc=xemul@parallels.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).