K3B Won't Write - Permissions Problem?

[devnulljp]

I can't get K3B to write CDRs -- looks like some kind of permissions problem, but I'm at a loss to fix it.

Settings->Configure K3b->Programs->Permissions looks like this



Only those 3 programs show up in the permissions pane. I altered the permissions as recommended, but it makes no difference.

If I start k3b as root and choose configure k3b, I get this

In order to give K3b full access to the writer device the current user needs be added to a group cdrom.
The Permission helper that could do this for you was not enabled during build.
Please rebuild the package with the Permission helper enabled or contact your distribution.

My user is already a member of the cdrom group.

Burning, whether as root or as a normal user gives

cdrecord returned an unknown error (code 255)
Sometimes using TAO writing mode solves this issue

which of course it doesn't.

I should note that this error is new since I changed the permissions to those shown above. Before that, it bailed with ""cdrecord has no permission to open the device"

Here's the relevant section of the log

Errno: 5 (Input/output error), write_g1 scsi sendcmd: no error
CDB:  2A 00 FF FF CF 24 00 02 A0 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 03 00 00 00 00 0A 00 00 00 80 0C 00 00 00
Sense Key: 0x3 Medium Error, Segment 0
Sense Code: 0x0C Qual 0x00 (write error) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 13.750s timeout 200s
/usr/bin/wodim: Could not write Lead-in.
SAO startsec: -12508
Writing lead-in...
write CD-Text data: error after 0 bytes
Writing  time:   13.845s
/usr/bin/wodim: fifo had 191 puts and 0 gets.
/usr/bin/wodim: fifo was 0 times empty and 0 times full, min fill was 100%.

cdrecord command:
-----------------------
/usr/bin/wodim -v gracetime=2 dev=/dev/sr0 speed=24 -sao driveropts=burnfree textfile=/tmp/k3b.h18167 -useinfo -audio /tmp/k3b_audio_0_01.inf /tmp/k3b_audio_0_02.inf /tmp/k3b_audio_0_03.inf /tmp/k3b_audio_0_04.inf /tmp/k3b_audio_0_05.inf /tmp/k3b_audio_0_06.inf /tmp/k3b_audio_0_07.inf /tmp/k3b_audio_0_08.inf

Anyone else? Any ideas how to fix? I'm guessng it's permissions.

EDIT: Changed permissions for cdrdao and wodim to 0755, and it works.

[oshunluvr]

On my KDEneon 16.04 system, all those files are 0755, which translates to -rwxr-xr-x

Yours are 4711 which translates to -rws--x--x

Can't hurt to change the permissions and try again. You shouldn't be running K3B as root. root is not a member of the cdrom group

[oshunluvr]

Funny, I opened up K3B and it wanted me to changes the permissions to your setup. When I hit the refresh button, it crashed with a General Protection fault.

[devnulljp]

Thanks for the info -- I'll give it a try.
(Not usually running as root, but tried it when I got the permissions errors.)

EDIT: Brilliant, that fixed it.

Wonder why k3b recommended the wrong permissions?

Thanks

[oshunluvr]

Either it's a bug or doesn't work with *buntu distros.

The "4" of 4711 means the setuid bit is on, which to my understand means "use the owner of the file UID when executing" - in other words it sets the user id to the owner of the file when any user attempts to execute it. So in this case, as long as K3B has the permission to execute the file, it should execute as "root". So following the logic, it seems like it should work, but obviously it doesn't.

No telling why without further digging...