MacBSD symbolic links in /tmp

MacBSD symbolic links in /tmp

Post by David Sacerdo » Sat, 17 Jun 1995 04:00:00



I recently noticed that any symbolic links created in /tmp on a MacBSD
system I was helping a friend set up were automatically chowned to root.  
This has obvious positive implications in terms of making race conditions
harder to exploit.  Does anybody see any negative implications to this,
and what do people think of encouraging vendors to adopt a similar strategy?
                        David Sacerdote
 
 
 

MacBSD symbolic links in /tmp

Post by Neil Wood » Mon, 19 Jun 1995 04:00:00


: I recently noticed that any symbolic links created in /tmp on a MacBSD
: system I was helping a friend set up were automatically chowned to root.  
: This has obvious positive implications in terms of making race conditions
: harder to exploit.  Does anybody see any negative implications to this,
: and what do people think of encouraging vendors to adopt a similar strategy?
:                       David Sacerdote

If I remember correctly, this behaviour was considered a bug, and
has been fixed (symlink owner set to owner of directory).

I don't see how the above behaviour can make race conditions harder
to exploit (if we were trying to race a file open in /tmp, we could
create the symbolic link to point to a directory where we can remove
symlinks).

Cheers,

Neil
--
Let the Mystery Be, So Watcha Want, Longing In Their Hearts, Hate My Way,
M-Bike, Safari, Uncle June and Aunt Kiyoti, Daisy Dead Petals, Tuff Gnarl.

     ...like a badger with an afro throwing sparklers at the Pope...

 
 
 

MacBSD symbolic links in /tmp

Post by David Sacerdo » Mon, 19 Jun 1995 04:00:00


: If I remember correctly, this behaviour was considered a bug, and
: has been fixed (symlink owner set to owner of directory).

: I don't see how the above behaviour can make race conditions harder
: to exploit (if we were trying to race a file open in /tmp, we could
: create the symbolic link to point to a directory where we can remove
: symlinks).

You're right.  Thanks.
                David Sacerdote

 
 
 

1. Too many symbolic links, Symbolic link loop

Hello,

I'm fighting with a FreeBSD machine. Roughly what I'm up to: I clean
installed FreeBSD, with the DES option. The goal is to set up an Apache
on the machine. Then I performed a rdist from a BSDI machine, importing
stuff like password file, user directories, user quotas, shells. The
Apache works
just fine, but when I try to run Perl I get stuck with the error
message:
"Too many symbolic links" (under bash), "Symbolic link loop" (under sh).
I've
scanned through my symbolic links w/o finding something striking.
Basically, the
links I have are "shortcuts to shells", some links to user logs...
Anyone seen this kind of problem? Anyone solved it? How?

        Cheers

                Michael
--
Michael Hallgren, Easynet France
Write : http://www.loria.fr/tex
Play : http://www.perl.com/perl

2. Help: XF86Config file setup

3. Broken symbolic link to /tmp in SCO OpenServer v5.0.0

4. Jitterbug

5. dangers of linking /var/tmp -> /tmp

6. Setting up ".com" -- How?

7. link /var/tmp to /tmp

8. downgrading glibc

9. symbolic link not a real link

10. kill symbolic link along with the linked file?

11. symbolic link not a real link

12. regular link of a symbolic link

13. A hard link or a symbolic link?