Red Hat Bugzilla – Bug 201184
xsane lacks permission to open scanner device
Last modified: 2007-11-30 17:11:39 EST
Description of problem: Using a USB scanner. When I fire up xsane, it pops up a
box saying "scanning for devices" and then after a short bit says "no devices
available." If I run it as root, then it finds the scanner. If, as root, I do
"chmod 666" on the device pointed to by the symlink /dev/scanner-usbdev2.x,
where x is the scanner address, then I can run xsane as a normal user.
So the problem is probably not with xsane but with whatever component of the
system creates the scanner device when the scanner is plugged into the USB port.
I don't know enough about linux internals to know what component that is.
Version-Release number of selected component (if applicable):
So far, two out of two times.
Steps to Reproduce:
1.Turn on USB scanner and plug into computer.
2.Start xsane as non-priv user
3.See message "no devices available"
4.As root, do this:
chmod 666 /dev/scanner-usbdev*
5.Repeat step 2
4.See xsane gui ready for action.
The chmod step is necessary for non-priv user to run xsane.
Should see xsane gui ready for action without needing the chmod step.
Created attachment 133555 [details]
Excerpts from /var/log/messages related to USB and xsane
What kind of scanner (preferably with USB vendor and product id) and which
version of sane-backends do you have?
The scanner is an Epson Perfection 1200U PHOTO USB scanner.
I don't know the USB vendor & product ID.
Please find out the USB vendor and product ID by running the "lsusb" command
(from the "usbutils" package) as root and posting the output.
[root@pascal ~]# lsusb
Bus 004 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000
Bus 002 Device 006: ID 04b8:0104 Seiko Epson Corp. Perfection 1200
Bus 002 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Created attachment 135420 [details]
output of ``rpm -qa -last'' truncated to updates after Aug 4.
The component that changed to fix this bug must be in this list.
The problem has gone away. Since I didn't use the scanner since about August 3,
I can't tell exactly when the bug was fixed. It was not anything in xsane since
that has not been updated. The behavior now is that the device pointed to by
/dev/scanner-usbdev* is owned by whoever is logged in, so xsane has permission
to open it. Looking at the list, I think most likely the fix came with
kernel-2.6.17-1.2174_FC5 or gnome-session-2.14.3-1.fc5.