From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: Andrew Morton <akpm00@gmail.com>,
linux-kernel@vger.kernel.org, containers@lists.osdl.org,
linux-fsdevel@vger.kernel.org,
Kirill Shutemov <kirill@shutemov.name>,
Pavel Emelyanov <xemul@parallels.com>,
James Bottomley <jbottomley@parallels.com>,
Nathan Lynch <ntl@pobox.com>, Zan Lynx <zlynx@acm.org>,
Daniel Lezcano <dlezcano@fr.ibm.com>,
Vasiliy Kulikov <segoon@openwall.com>, Tejun Heo <tj@kernel.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/ directory v12
Date: Wed, 14 Sep 2011 15:39:12 +0400 [thread overview]
Message-ID: <20110914113912.GQ25367@sun> (raw)
In-Reply-To: <20110914111437.GA22516@atrey.karlin.mff.cuni.cz>
On Wed, Sep 14, 2011 at 01:14:38PM +0200, Pavel Machek wrote:
> Hi!
>
...
> >
> > Pavel, I somehow lost. What exactly the security issue here? There are a few
> > patches from Vasiliy in -mm queue at moment. In particular one includes
> > .permission set for fd/ handling. So I've updated the map_files as well
> > (it's below). So please review and point me where the problem
> > is. Thanks!
>
> AFAICT, this recreates existing problem with /proc/<pid>/fd (see
> discussion at
>
> http://www.securityfocus.com/archive/1/507386/30/0/threaded
>
> ). It creates object that looks like symlink, but does not behave as
> one, and permissions of directories are not checked as they would be
> if it was a symlink.
>
> Pavel
OK, so the problem is that we might return a path to the file mapped
even if the directory which consists the former file has its permission
changed, right? For example, lets say we have
| lr-x------ 1 cyrill cyrill 64 Sep 14 19:35 /proc/self/map_files/3d73a00000-3d73a1c000 -> /lib64/ld-2.5.so
and once /lib64 became unreadable we should not return the path to
3d73a00000-3d73a1c000 as well, that is what you mean, right?
Cyrill
next prev parent reply other threads:[~2011-09-14 11:39 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-13 21:13 [patch 0/2] symlinks for mapped files in proc Cyrill Gorcunov
2011-09-13 21:14 ` [patch 1/2] fs, proc: Make proc_get_link to use dentry instead of inode Cyrill Gorcunov
2011-09-14 1:37 ` Kirill A. Shutemov
2011-09-13 21:14 ` [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/ directory v12 Cyrill Gorcunov
[not found] ` <20110914023428.GA4034@shutemov.name>
2011-09-14 5:54 ` Cyrill Gorcunov
2011-09-14 6:52 ` Andrew Morton
2011-09-14 10:56 ` Cyrill Gorcunov
2011-09-14 11:14 ` Pavel Machek
2011-09-14 11:39 ` Cyrill Gorcunov [this message]
2011-09-14 13:44 ` Cyrill Gorcunov
2011-09-14 14:48 ` Vasiliy Kulikov
2011-09-14 14:57 ` Vasiliy Kulikov
2011-09-14 16:00 ` Cyrill Gorcunov
2011-09-14 16:07 ` Vasiliy Kulikov
2011-09-14 16:13 ` Pavel Emelyanov
2011-09-14 16:21 ` Vasiliy Kulikov
2011-09-15 9:14 ` Cyrill Gorcunov
2011-09-15 9:27 ` Vasiliy Kulikov
2011-09-15 10:29 ` Cyrill Gorcunov
2011-09-15 10:56 ` Vasiliy Kulikov
2011-09-15 11:00 ` Cyrill Gorcunov
2011-09-15 20:19 ` Cyrill Gorcunov
2011-09-16 17:56 ` Vasiliy Kulikov
2011-09-16 18:07 ` Cyrill Gorcunov
2011-09-16 18:11 ` Vasiliy Kulikov
2011-09-16 18:26 ` Cyrill Gorcunov
2011-09-16 18:31 ` Kirill A. Shutemov
2011-09-16 18:40 ` Cyrill Gorcunov
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