Bug 5050 - hp and hpfax cups backends crash on Ubuntu when we restart cups from tl-setup
Summary: hp and hpfax cups backends crash on Ubuntu when we restart cups from tl-setup
Status: CLOSED FIXED
Alias: None
Product: ThinLinc
Classification: Unclassified
Component: Server OS (show other bugs)
Version: trunk
Hardware: PC Unknown
: P2 Normal
Target Milestone: 4.2.0
Assignee: Pierre Ossman
URL:
Keywords: hean01_tester, prosaic
Depends on:
Blocks:
 
Reported: 2014-03-28 13:02 CET by Pierre Ossman
Modified: 2014-05-02 10:13 CEST (History)
1 user (show)

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Description Pierre Ossman cendio 2014-03-28 13:02:11 CET 
Seen on Ubuntu 14.04 beta 2:

ERROR: apport (pid 9856) Fri Mar 28 04:51:23 2014: another apport instance is already running, aborting
ERROR: apport (pid 9857) Fri Mar 28 04:51:23 2014: called for pid 9854, signal 11, core limit 0
ERROR: apport (pid 9857) Fri Mar 28 04:51:23 2014: script: /usr/lib/cups/backend/hpfax, interpreted by /usr/bin/python2.7 (command line "/usr/bin/python /usr/lib/cups/backend/hpfax")
ERROR: apport (pid 9857) Fri Mar 28 04:51:23 2014: is_closing_session(): no DBUS_SESSION_BUS_ADDRESS in environment
ERROR: apport (pid 9857) Fri Mar 28 04:51:25 2014: wrote report /var/crash/_usr_lib_cups_backend_hpfax.7.crash
ERROR: apport (pid 9932) Fri Mar 28 04:51:27 2014: called for pid 9920, signal 11, core limit 0
ERROR: apport (pid 9932) Fri Mar 28 04:51:27 2014: executable: /usr/lib/cups/backend/hp (command line "hp")
ERROR: apport (pid 9932) Fri Mar 28 04:51:27 2014: is_closing_session(): no DBUS_SESSION_BUS_ADDRESS in environment
ERROR: apport (pid 9932) Fri Mar 28 04:51:27 2014: wrote report /var/crash/_usr_lib_cups_backend_hp.7.crash
ERROR: apport (pid 9934) Fri Mar 28 04:51:27 2014: another apport instance is already running, aborting

Popped up two nasty graphical error messages as well when tl-setup was running.
Comment 1 Pierre Ossman cendio 2014-04-03 13:56:03 CEST 
Seems to be something we are doing. tl-setup consistently causes the backends to crash, but "sudo service cups restart" does not.
Comment 2 Pierre Ossman cendio 2014-04-03 14:09:12 CEST 
Actually, it's not the restart that causes it, but instead this command:

   $ lpinfo -h localhost -v

You don't even have to have to be root, or have ThinLinc installed.
Comment 3 Pierre Ossman cendio 2014-04-03 14:23:58 CEST 
Same bug exists in Ubuntu 13.10. Can't find any reports in Launchpad though...
Comment 4 Pierre Ossman cendio 2014-04-04 13:19:23 CEST 
Reported to ubuntu:

https://bugs.launchpad.net/ubuntu/+source/hplip/+bug/1302437

Now to decide if we want to work around their bug. It would mean loss of functionality though as we cannot confirm that the backend was installed properly.
Comment 5 Pierre Ossman cendio 2014-04-04 14:14:36 CEST 
Apparently the bug is that hplip fails to handle when there is no USB controller in the machine. So it is very likely this won't affect installations on physical machines. On virtual servers it difficult to say how common it will be.
Comment 6 Pierre Ossman cendio 2014-04-08 14:10:51 CEST 
Ubuntu has released an updated hplip package for 14.04, completely removing this issue.
Comment 7 Henrik Andersson cendio 2014-04-30 08:57:49 CEST 
Verified that this is not an issue on a physical machine using ubuntu 13.10-
Comment 8 Henrik Andersson cendio 2014-04-30 09:06:07 CEST 
(In reply to comment #7)
> Verified that this is not an issue on a physical machine using ubuntu 13.10-

Booted using kernel param nousb and following error was produced:

[   65.755276] type=1400 audit(1398841457.389:69): apparmor="DENIED" operation="open" parent=1902 profile="/usr/sbin/cupsd" name="/dev/" pid=1918 comm="usb" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
[   65.841853] hp[1908]: segfault at 30 ip 00007f3dec232f74 sp 00007fff285b4660 error 4 in libpthread-2.17.so[7f3dec229000+17000]
[   66.367581] hpfax[1903]: segfault at 30 ip 00007f83ad384f74 sp 00007fff092a6e50 error 4 in libpthread-2.17.so[7f83ad37b000+17000]
Comment 9 Henrik Andersson cendio 2014-05-02 10:13:16 CEST 
Verified as working on a updated ubuntu 14.04 LTS, no apport issues nor crashes in kernel log.
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