11

A few days ago I realized my Ubuntu machine wouldn't load after login. After some digging around on a liveCD I realized my HDD was at 100% capacity, so I deleted some large files and was able to log in. I didn't have sudo permissions any more and had to boot into recovery mode and change the sodoers file, but eventually recovered root permissions.

I then noticed my machine was a little sluggish, and top was showing cupsd using 100% CPU. I've never seen this program before but I soon realized it was a legitimate program.

I the deleted about 40GB worth of videos, only to see my drive space deplete almost instantly in front of my eyes. With a little research and intuition, I realized it might be a a log file being blown up, and sure enough ls -lh /var/log/cups/ shown me an error_log file that was 80GB+ large.

I deleted the file sudo rm -rf /var/log/cups/error_log, killed the service with sudo service cups end, and went on my business. I realized after that it would have been a good idea to check out the contents of error_log before I deleted it, but I wanted to get rid of the thing before I was locked out again.

That was yesterday. Today, I started my laptop again and saw cupsd running again at 100% cpu, and sure enough I see my disk space depleting. I stopped the service and run tail -f /var/log/cups/error_log, and there are millions of lines of this:

W [15/Jul/2015:11:23:03 -0700] Notifier for subscription 911 (dbus://) went away, retrying!
E [15/Jul/2015:11:23:03 -0700] File "/usr/lib/cups/notifier/dbus" has insecure permissions (0100777/uid=0/gid=0).

==EDIT=================================================================

ls -l /usr/lib/cups/notifier/dbus shows permissions and ownership as -rwxrwxrwx 1 root root when they should be -rwxr-xr-x 1 daemon root, as described in the comments. sudo chown root:root /usr/lib/cups/notifier/dbus also did not fix the ownership problems.

Finally I removed and reinstalled cups, but to no avail. These links were given as potentially helpful guides,(accidentally chmod -R on /,restore chown permissions) but they ultimately result in suggesting a reinstall of the OS itself.

Community
  • 1
wndg
  • 111
  • 1
  • 1
  • 5
  • What is the output of ls -l /usr/lib/cups/notifier/dbus? I had a similar problem a long time ago and the only easy way to solve it was to disable CUPS... (no printing then) – Wilf Jul 15 '15 at 18:41
  • 1
    -rwxrwxrwx 1 root 14k Sep 5 2014 /usr/lib/notifier/dbus – wndg Jul 15 '15 at 20:08
  • 1
    What does cups do anyway? I mean if it can be disabled without serious repercussion .... – wndg Jul 15 '15 at 20:09
  • 1
    It does most of the stuff for printing, so without it you can't print. I think the permissions on the file should be -rwxr-xr-x (thats what the permissions are on my Ubuntu 14.04 install), so you may be able to fix the problem by running sudo chmod 755 /usr/lib/cups/notifier/dbus (and then restarting CUPs or the computer). – Wilf Jul 15 '15 at 20:17
  • 1
    Printing as in printing paper? The permissions are now -rwxr-xr-x however after restart cupsd still runs at 95%+ and creating large error_log file (however seemingly not as quickly?). – wndg Jul 15 '15 at 20:43
  • Has the contents of the log changed? Printing as in printing paper yes, some PDF printy things may need it as well. – Wilf Jul 15 '15 at 20:55
  • First, sorry for the intermittent reply, we just cancelled our wifi in the house and I'm on my phone. The log has the same error messages. – wndg Jul 16 '15 at 01:42

4 Answers4

17

For Ubuntu 15.10 what worked for me was:

sudo service cups stop
sudo rm /etc/cups/subscriptions.conf*
sudo rm -r /var/cache/cups
sudo service cups start

(If you cannot stop cups try):

ps aux | grep cups

Get process id (pid) from output and:

kill -9 (pid you have learned here)
Mostafa Ahangarha
  • 4,408
salihcenap
  • 539
3

On Debian 9

  1. user@machine: sudo su

  2. root@machine: 

chown -R root:root /usr/lib/cups/* && \
chmod -R 755 /usr/lib/cups/* && \
/etc/init.d/cups restart

return:

ok Restarting cups via systemctl cups.service

and save my log and my cpu

Nolwennig
  • 131
1

I am unable to comment, so this is in the form of an answer: 

sudo chown root:root /usr/lib/cups/notifier/dbus

might help, now that you have the permissions right. Who is user 1 on your system? If you don't know how the permissions/ownership of the file were changed from the default, the problem might be the tip of an iceberg. If so, reinstalling would be advisable.

JEL
  • 176
  • 7
  • I ran the command and restarted and nothing seemed to change. Not sure how to find out who user 1 is. What do you think could be "the rest of the iceberg" as you put it...? – wndg Jul 16 '15 at 01:56
  • User 1 on a newly installed Ubuntu system is daemon. That your ls command returned -rwxrwxrwx 1 root as opposed to -rwxr-xr-x daemon root suggests corrupted or missing system files. The daemon user, 1, is not associated with a name in /etc/passwd. – JEL Jul 16 '15 at 02:05
  • I just looked at /etc/passwd and user 1 was daemon, but I guess your say my problem is not associated with that. How would I find who user 1 is then? – wndg Jul 16 '15 at 02:11
  • If user 1 is daemon in passwd, that's what ls should show as the user owning the dbus file. Have you tried re-installing cups? Be sure to back up /etc/cups first. – JEL Jul 16 '15 at 02:16
  • Edit: id daemon gives me uid=1(daemon) gid=1(daemon) groups=1(daemon) – wndg Jul 16 '15 at 02:20
  • I can try that but I'll need to find internet first. – wndg Jul 16 '15 at 02:21
  • Any local configuration you've done should be preserved in your backup of /etc/cups, so you can restore it from there. After reinstalling, check that the output of ls -l for the dbus file is correct: user=root, group=root, permissions as noted previously. – JEL Jul 16 '15 at 02:32
  • Have a look at this discussion, also: http://askubuntu.com/questions/43621/what-if-i-accidently-run-command-chmod-r-on-system-directories-etc – JEL Jul 16 '15 at 02:49
  • And this discussion, http://askubuntu.com/questions/300557/how-to-restore-the-default-chown-permissions-on-a-directory-file which describes symptoms very similar to what you've described, including the runaway error_log messages. The discussion refers to the discussion at the link in my previous comment, and the upshot (downshot?) of both is that reinstalling the entire system is recommended. Good luck. – JEL Jul 16 '15 at 03:03
  • I've re-downloaded cups (sudo apt-get remove cups, sudo apt-get install cups) and this message caught my eye when installing:

    WARN: / is world writable! WARN: / is group writable! WARN: /usr/sbin/ufw is world writable! WARN: /usr/sbin/ufw is group writable! WARN: /usr/sbin is world writable! WARN: /usr/sbin is group writable! WARN: /usr is world writable! WARN: /usr is group writable!

    Also, ls -l /usr/lib/cups/notifier/dbus still shows root root.

     – wndg Jul 16 '15 at 03:54
  • I am guessing it already is owned by root from the rwxrwxrwx 1 root 14k Sep 5 2014 /usr/lib/notifier/dbus ls-l output.... @wndg could you edit that info into your question so it is readable, and have you modified the permissions on / at any point (and is disabling CUPS a suitable answer)? – Wilf Jul 16 '15 at 06:49
  • @wndg, Those warnings are about the iceberg I mentioned earlier. If you want to try to fix the permissions/ownership problems, see the links I provided to other discussions for some possible techniques, but probably the least time-consuming solution is re-installing Ubuntu. Be sure to back up any extensive configuration changes you've made along with any personal files, and check permissions and ownership carefully before replacing saved configuration files, etc. in the new installation. – JEL Jul 16 '15 at 06:51
  • I think I'm going to reinstall. I've had a stable Ubuntu machine for 2 years now and seemingly something bazaar has happened, either to me or because of me. @Wilf I don't recall ever modifying permissions in that fashion, no. The last thing I can remember, this all started after I hooked up my friend's iPhone to my computer to pull some photos from it. Thanks everyone for the help. – wndg Jul 16 '15 at 17:44
  • I had accidentally messed up my permissions and ownership by using chown on /. Had to spend an evening clearing that up but this I saw a few days back. And your solution fixed it straight away. Putting this in a comment if anyone finds themselves in similar situation – Thermal_insulator Apr 18 '23 at 12:23
1

simply done it ,It's working for me :

1) sudo chmod 755 /usr/lib/cups/notifier/

2) ll /usr/lib/cups/notifier/

3) sudo /etc/init.d/cups restart

done it !!!

WinEunuuchs2Unix
  • 102,282
Avani badheka
  • 2,436