From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041111 Firefox/1.0 Description of problem: When I try to burn iso image as normal user, cdrecord fails with following message: "cdrecord: Cannot allocate memory. Cannot get SCSI I/O buffer." The same procedure running as root makes correct CD. The iso image I try to burn and command used to burn the CD they are successfully tested on another Linux system. I also explored that if I run the recording procedure and tracing it with strace (typicaly "strace cdrecord ...") it burns the CD correctly. I did not found any a logs in my logfile (/var/log/messages). Version-Release number of selected component (if applicable): cdrecord-2.01.1-5 How reproducible: Always Steps to Reproduce: 1.Assume you have following: -correct iso image called iso.iso in your home dir. -link /dev/cdrom points to your IDE CD Recorder device. 2.Login as normal user and go to you home directory. 3. Try to execute following command: cdrecord dev=/dev/cdrom iso.iso Actual Results: [myuser@mypc myuser]$ cdrecord dev=/dev/cdrom iso.iso cdrecord: No write mode specified. cdrecord: Asuming -tao mode. cdrecord: Future versions of cdrecord may have different drive dependent defaults. cdrecord: Continuing in 5 seconds... Cdrecord-Clone 2.01-dvd (i686-pc-linux-gnu) Copyright (C) 1995-2004 J�rg Schilling Note: This version is an unofficial (modified) version with DVD support Note: and therefore may have bugs that are not present in the original. Note: Please send bug reports or support requests to http://bugzilla.redhat.com/bugzilla Note: The author of cdrecord should not be bothered with problems in this version. scsidev: '/dev/cdrom' devname: '/dev/cdrom' scsibus: -2 target: -2 lun: -2 Linux sg driver version: 3.5.27 Using libscg version 'schily-0.8'. cdrecord: Warning: using inofficial libscg transport code version (schily - Red Hat-scsi-linux-sg.c-1.83-RH '@(#)scsi-linux-sg.c 1.83 04/05/20 Copyright 1997 J. Schilling'). cdrecord: Cannot allocate memory. Cannot get SCSI I/O buffer. Expected Results: [root@mypc myuser]# cdrecord dev=/dev/cdrom iso.iso cdrecord: No write mode specified. cdrecord: Asuming -tao mode. cdrecord: Future versions of cdrecord may have different drive dependent defaults. cdrecord: Continuing in 5 seconds... Cdrecord-Clone 2.01-dvd (i686-pc-linux-gnu) Copyright (C) 1995-2004 J�rg Schilling Note: This version is an unofficial (modified) version with DVD support Note: and therefore may have bugs that are not present in the original. Note: Please send bug reports or support requests to http://bugzilla.redhat.com/bugzilla Note: The author of cdrecord should not be bothered with problems in this version. scsidev: '/dev/cdrom' devname: '/dev/cdrom' scsibus: -2 target: -2 lun: -2 Linux sg driver version: 3.5.27 Using libscg version 'schily-0.8'. cdrecord: Warning: using inofficial libscg transport code version (schily - Red Hat-scsi-linux-sg.c-1.83-RH '@(#)scsi-linux-sg.c 1.83 04/05/20 Copyright 1997 J. Schilling'). Device type : Removable CD-ROM Version : 0 Response Format: 1 Vendor_info : 'HL-DT-ST' Identifikation : 'RW/DVD GCC-4520B' Revision : '1.00' Device seems to be: Generic mmc2 DVD-ROM. Using generic SCSI-3/mmc CD-R/CD-RW driver (mmc_cdr). Driver flags : MMC-2 SWABAUDIO BURNFREE Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R Speed set to 1762 KB/s Starting to write CD/DVD at speed 10.0 in real TAO mode for single session. Last chance to quit, starting real write 0 seconds. Operation starts. trackno=0 Track 01: Total bytes read/written: 43745280/43745280 (21360 sectors). Additional info: I have correctly set cdrecord suid bits. -rwsr-xr-x 1 root root 329612 ř�j 18 15:56 /usr/bin/cdrecord My system is runnig on following kernel (output of uname -a): Linux kink 2.6.9-1.667 #1 Tue Nov 2 14:41:25 EST 2004 i686 athlon i386 GNU/Linux This bug happens after I installed FC3 and updated it from internet by command (I did not tried burn CDs before yum update): yum -y update Folloving straced recording procedure produce correct CD: strace cdrecord dev=/dev/cdrom iso.iso
hint: do not suid cdrecord!!!
here are some links to others having the same problem and fixes. looks like its caused by a change in the kernel source. maybe it slipped thru fedora's Q&A process? scroll down about 1/2 way on both. http://kerneltrap.org/node/view/4022 http://kerneltrap.org/node/view/4026
If I understood it correctly, we have a cdrecord bug here. There are many people saying that we shouldn't set SUID on cdrecord, but without it, I cannot do anything without getting buffer underuns since my drive is too fast for its internal buffer (48X, 2MB). During cd burning, if the kernel is occupied and doesn't schedule cdrecord for more than a quarter of a second, i have a buffer underrun. So, running cdrecord without SUID is not an option. The fix seems reasonably simple, cdrecord should just drop root privileges on an earlier stage. I would say that this sould be a high-priority issue. After this kernel upgrade, I'm having to run cdrecord/k3b as root to avoid losing media.
An update has been released for Fedora Core 3 (kernel-2.6.12-1.1372_FC3) which may contain a fix for your problem. Please update to this new kernel, and report whether or not it fixes your problem. If you have updated to Fedora Core 4 since this bug was opened, and the problem still occurs with the latest updates for that release, please change the version field of this bug to 'fc4'. Thank you.
This bug has been automatically closed as part of a mass update. It had been in NEEDINFO state since July 2005. If this bug still exists in current errata kernels, please reopen this bug. There are a large number of inactive bugs in the database, and this is the only way to purge them. Thank you.