I get an error when running crontab as user:
/var/spool/cron/crontabs/ac: Permission denied
Googling shows a few people with a similar problem but either no
solution or one that doesn't work here (crontab not having setguid or
not in the crontab group).
The permissions are:
drwx-wx--T 2 root root 4096 Jan 24 10:24 /var/spool/cron/crontabs/
-rwxr-sr-x 1 root crontab 27724 May 13 2009 /usr/bin/crontab*
-rw------- 1 ac crontab 919 Dec 2 10:04 /var/spool/cron/crontabs/ac
These are the same as I get on other computers where crontab works
correctly. I had the nasty thought that my system might have been
compromised but I have no other evidence for that. Chkrootkit doesn't
show anything.
Only possible clue: /var/spoo/cron/crontabs/ac has this:
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.xScslJ/crontab installed on Wed Dec 2 10:04:38 2009)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
I don't have any such file in /tmp.