Markus Huber wrote: > Just installed the kernel#2.6.8-1.521, and the CD-RW is not recognized > as CD-Writer anymore. Under kernel#2.6.7-1.494.2.2 it still works > perfectly. I wonder if anybody else experiences that problem. > > Here some useful (?) details & logs: > > The device is listed in the hardwarebrowser as > ATAPI CD-RW 52x24 > Device: /dev/hdc > > That's perfect, at least it was. > > The log for "nautilus --no-desktop burn:" is: > > cdrecord: Illegal write mode for this drive. > cdrecord: Drive does not support TAO recording. > SCSI buffer size: 64512 > cdrecord: Warning: using inofficial libscg transport code version > (schily - Red Hat-scsi-linux-sg.c-1.80-RH '@(#)scsi-linux-sg.c 1.80 > 04/03/08 Copyright 1997 J. Schilling'). > Linux sg driver version: 3.5.27 > Warning: Open by 'devname' is unintentional and not supported. > scsibus: -2 target: -2 lun: -2 > devname: '/dev/hdc' > scsidev: '/dev/hdc' > cdrecord: WARNING: This causes a high risk for buffer underruns. > cdrecord: Permission denied. WARNING: Cannot set priority using > setpriority(). > cdrecord: Operation not permitted. WARNING: Cannot set RR-scheduler > cdrecord: WARNING: This causes a high risk for buffer underruns. > cdrecord: Cannot allocate memory. WARNING: Cannot do mlockall(2). > cdrecord: Continuing in 5 seconds... > cdrecord: Future versions of cdrecord may have different drive dependent > defaults. > cdrecord: Asuming -tao mode. > cdrecord: No write mode specified. > > I do not have a clue, because it happens just with this kernel, and I > don't find any information about that problem with the 2.6.8-kernel > through google. If anyone has a LWN subscription, try looking at http://lwn.net/Articles/98379/ for a good summary of the situation. Brief workaround: run your CD recording program from a root shell, or use sudo. The problem is that CD recording needs some pretty low-level commands to run. In http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&threadm=2tY9w-713-39%40gated-at.bofh.it&prev=/groups%3Fdq%3D%26num%3D100%26hl%3Den%26lr%3D%26ie%3DUTF-8%26group%3Dlinux.kernel%26start%3D400 (sorry about the length of that!), Alan Cox explains > With the current code I can destroy all your hard disks given read > access to the drive. With checks on writable I can destroy all your hard > disks/cdroms as appropriate with write access. > > Destroy here means "dead, defunct, pushing up the daisies, go order > a new one kind of dead". It's considered that being able to do this as a non-root user is a security bug. Better, more complex workarounds are being worked on: it's likely that we're going to see cd writing special cased, and only the commands needed for that allowed through. James. -- E-mail address: james | Never ask, "Oh, why were things so much better @westexe.demon.co.uk | in the old days?" | It's not an intelligent question. | -- Ecclesiastes 7 v. 10
