Bugtraq mailing list archives
Re: Re: /proc filesystem allows bypassing directory permissions on Linux
From: nomail () nomail com
Date: Mon, 26 Oct 2009 09:14:30 -0600
I do not think mounting /proc should change access control semantics.It didn't in fact change anything. If the guest created hardlink to that file in a unrestricted location, what would you say?
Do your homework and test it. You can't create the hardlink - the link(oldpath, newpath) call will fail with EACCES if search permission is denied for any directory in oldpath or newpath. Documented in the manpage, and I just tested and verified it. Fact is, directory permissions are relevant in Unix. Despite it's permissions, under the Unix access permission semantics the file is unwriteable for anyone but the owner, and this bug pokes a hole into that.
Current thread:
- Re: /proc filesystem allows bypassing directory permissions on Linux, (continued)
- Re: /proc filesystem allows bypassing directory permissions on Linux Pavel Kankovsky (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Pavel Kankovsky (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Tony Finch (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Matthew Dempsky (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Tony Finch (Oct 27)
- Re: /proc filesystem allows bypassing directory permissions on Linux Matthew Dempsky (Oct 28)
- Re: /proc filesystem allows bypassing directory permissions on Linux psz (Oct 28)
- Re: /proc filesystem allows bypassing directory permissions on Linux Glynn Clements (Oct 29)
- Re: /proc filesystem allows bypassing directory permissions on Linux Matthew Dempsky (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Pavel Kankovsky (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux psz (Oct 27)
- Re: /proc filesystem allows bypassing directory permissions on Linux Pavel Machek (Oct 27)
- Re: /proc filesystem allows bypassing directory permissions on Linux Kinzel, David (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Dan Yefimov (Oct 26)
- Re: /proc filesystem allows bypassing directory permissions on Linux Dan Yefimov (Oct 27)