[cups.bugs] [HIGH] STR #2441: Wrong owner of /dev/lp0

[Hans-Olof Hansson]

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[STR New]

The problem is that cups runs with the owner lp:lp and since /dev/lp0 has
the owner root:lp it is not possible to print at the parallel-port of the
computer. Changing the owner to lp:lp for the device-driver solves the
problem, for a while, until next reboot since the /dev-file system appears
to be a virtual file system. All permissions of the /dev-file is managed by
the udev permission rules. The udev and cups thus seems not to be
compatible. In order to avoid other potential problem I think that cups
has to change it's permissions/running user from lp:lp to root:lp.

The problem is known to exist in at least two different Linux
distributions as shown below. 

Kubuntu 5.10
http://ubuntuforums.org/showthread.php?t=39354

OpenSUSE 10.2
http://www.linuxportalen.se/node/6791#comment-39924
(see problem#1, swedish only. Sorry. Translation could be arranged, if
required.)

How to reproduce:
On a new installed system (or a rebooted one)
- the file /dev/lp0 has the owner root:lp
- cups runs with owner lp:lp
=> cups should now not be able to print on the parallel port. 

Many user have silently (see Kubuntu link above) patched the udev rules or
the /dev/lp0 files manualy, thus masking the real problem.

Link: http://www.cups.org/str.php?L2441
Version: 1.2.7