From: Daryl Tester <dt-lkml@handcraftedcomputers.com.au>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Sven Wegener <sven.wegener@stealer.net>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: PROBLEM?: "permission denied" when accessing /proc/self/fd/* after setuid
Date: Fri, 08 Aug 2008 11:54:48 +0930 [thread overview]
Message-ID: <489BAE70.5080909@handcraftedcomputers.com.au> (raw)
In-Reply-To: <20080808005049.GA20707@martell.zuzino.mipt.ru>
Alexey Dobriyan wrote:
> Something similar was fixed in 2.6.22, but let me check.
You're right - from <http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.22>:
commit 8948e11f450e6189a79e47d6051c3d5a0b98e3f3
Author: Alexey Dobriyan <adobriyan@openvz.org>
Date: Tue May 8 00:23:35 2007 -0700
Allow access to /proc/$PID/fd after setuid()
/proc/$PID/fd has r-x------ permissions, so if process does setuid(), it
will not be able to access /proc/*/fd/. This breaks fstatat() emulation
in glibc.
open("foo", O_RDONLY|O_DIRECTORY) = 4
setuid32(65534) = 0
stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied)
However, one of the kernels I tried this on (and failed) was a 2.6.24-19 -
is it possible this patch was backed out?
Cheers,
--dt
next prev parent reply other threads:[~2008-08-08 2:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-07 6:16 PROBLEM?: "permission denied" when accessing /proc/self/fd/* after setuid Daryl Tester
2008-08-07 15:20 ` Sven Wegener
2008-08-08 0:38 ` Daryl Tester
2008-08-08 0:50 ` Alexey Dobriyan
2008-08-08 2:24 ` Daryl Tester [this message]
2008-08-08 2:59 ` Daryl Tester
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=489BAE70.5080909@handcraftedcomputers.com.au \
--to=dt-lkml@handcraftedcomputers.com.au \
--cc=adobriyan@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sven.wegener@stealer.net \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.