Red Hat Bugzilla – Bug 52286
User's can't open devices
Last modified: 2007-04-18 12:36:10 EDT
Description of Problem:
Permission problems locking device.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Create a configuration 'ttyS0' as root using 'minicom -s'
2. Open device as a normal user.
[gthomas@hermes gthomas]$ minicom -o ttyS0
Device /dev/ttyS0 lock failed.
Reassigning to jbj who did the recent locking stuff...
Are you using
If not, upgrade to those packages, as there was a mismatch
between the two packages that caused this type of failure.
If the above versions don't work, please reopen this bug.
We (Red Hat) really need to fix this before next release.
What more detail can I provide? I installed Roswell(RC1). I tried to use
an existing minicom configuration which accesses one of my serial ports (I
upgraded from 7.1) and gor the 'Device lock' message above.
I then recreated the configuration (as root: minicom -s). When I run it
as a non-root user, same error.
Jeff suggested that I install minicom-1.83.1-15 (of course, he couldn't
point me to an RPM for it, so I built is from the SRPM he provided). I
then installed this and it still fails - exact same scenario.
No more information is needed, the management unit is just
doing their management thing :-)
Meanwhile, I had not looked at the -o ttyS0 pathway, only
the default "minicom -s" pathway when using a helper binary
to lock the device.
Another zig-zag. lockdev-1.0.0-13 has access(2) checks on the
device, errno's are now explicitly mapped through /usr/sbin/lockdev
helper status returns, and minicom-1.83.1-16 does it's own
access(2) to disambiguate lock failure from device access failure.
Make sure you have both lockdev-1.0.0-13 and minicom-1.83.1-16
packages installed for functionality, this will not be addressed through
dependencies as the fault is entirely contained in beta software. You
will also need lockdev-devel-1.0.0-13 in order to rebuild minicom (and
soon uucp) correctly.
Basically this is what is happening
1) minicom no longer needs setuid uucp access to /var/lock
as those permissions are handled by setgid lock /use/sbin/lockdev
2) minicom user still needs access to the device through
usual system administration.
3) the device access checks have been moved from the open to
the lock acquisition phase of minicom.