Red Hat Bugzilla – Bug 74606
CUPS severe failure mode if /var/tmp not writeable
Last modified: 2008-05-01 11:38:03 EDT
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Description of problem:
If /var/tmp is not writeable by the user attempting to print, and the user
invokes lpr reading from STDIN, the lpr process will spin out of control at 100%
CPU utilization and eventually consume all available memory, causing a kernel crash.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. chmod 755 /var/tmp (this was default on my install of RH 7.3)
2. alternatives --config print (select CUPS)
3. service lpd stop, service cups start
4. configure a cups printer via http://localhost:631
5. lpr (as non-priveleged user)
Actual Results: CPU pegged, memory leaks, eventual crash of system
Expected Results: lpr process should quietly wait for input
strace shows endless loop of 'error opening /var/tmp for write'
'chmod 1777 /var/tmp' fixes the problem, but this was not default permissions
for my install of RH 7.3.
this may indeed be a problem for CUPS developers to fix -- ie. graceful failure
/var/tmp _must_ be writeable, and this is the default on all versions of Red
(See what 'rpm -V filesystem' says; for me it gives no output on a clean