Red Hat Bugzilla – Bug 214925
udev ignores "MODE:="0666" in rules, sets to 0660 instead
Last modified: 2007-11-30 17:11:48 EST
Description of problem:
I can chmod 0666 /dev/hdc (my dvdburner) but udev resets to 0660 at reboot.
I need mode 0666 on my burner device so regular users can use k3b
I can set it to mode 0666 as root, but it is not persistent.
I have added the following rule to /etc/udev/rules.d/50-udev.rules
and output of udevtest /block/hdc shows following line:
create_node: creating device node '/dev/hdc', major = '22', minor = '0', mode =
'0666', uid = '0', gid = '6'
Funny thing is, I can take my rule out and udevtest /block/hdc will show it
creating /dev/hdc as mode 0640, when in reality it is ALWAYS 0660, not 0666 nor
Version-Release number of selected component (if applicable):
add a udev rule to change permission of the device for my burner
restart udev, nothing changes
chmod 666 burner
reboot, and it goes back to mode 660
Steps to Reproduce:
1. ls -l /dev/hdc # (or wherever dvdr is , should be mode 660 )
2. echo 'KERNEL=="hdc", MODE:="0666"' >> /etc/udev/rules.d/50-udev.rules
3. udevtest /block/hdc # make sure rule is okay, should show MODE = 0666
4. chmod 666 /dev/hdc #just for good measure, not necessary
5. ls -l /dev/hdc # will be mode 666 now
6. udevcontrol reload_rules
ls -l /dev/hdc # will be mode 660 after steps above
ls -l /dev/hdc # should be mode 666 after steps above
This is just an annoyance, I need mode 666 for regular users to be able to use
k3b to burn cd's or dvd's
":=" is wrong... "=" is correct
but... permissions are set by pam_console described in
The console user, who first logs on the console will own the device.. no need
from man 7 udev
":= Assign a value to a key finally; disallow any later changes,
which may be used to prevent changes by any later rules."
lo and behold, yes, if I log in at the console, I own the drive and k3b works!
My trouble is that I almost always connect to my machine via VNC. I suppose I
could login on a tty and leave it (rather than always running a local X server
that I'll never use).
I changed the <cdrom> line in 50-default.perm to default to 0666 instead of
0660, and k3b works via VNC now, regardless of whether or not I'm logged in or not.