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On Friday 27 January 2012 20:07:45 Samuli Suominen wrote: |
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> On 01/28/2012 02:41 AM, Mike Frysinger wrote: |
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> > On Friday 27 January 2012 19:18:07 Samuli Suominen wrote: |
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> >> On 01/28/2012 02:14 AM, Mike Frysinger wrote: |
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> >>> along these lines, why is cdrtools set*id ? if we have a "cdrom" |
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> >>> group, and we assign our cdroms/dvdroms to that group, then we already |
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> >>> have access control in place and can skip the set*id. |
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> >> |
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> >> cdrtools can't probe the drives without the binary being setuid, or the |
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> >> user belonging to the 'disk' group (and even that is not enough in some |
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> >> cases if the permissions vary) |
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> > |
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> > the drives are owned by the "cdrom" group and have group +rw. so if the |
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> > user is in the "cdrom" group, why can't they probe the drives ? |
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> > |
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> > "disk" owns the non-removable hard drives. |
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> > |
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> > $ ls -l /dev/sr0 /dev/sg0 /dev/sg6 |
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> > crw-rw---- 1 root disk 21, 0 Jan 6 23:07 /dev/sg0 |
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> > crw-rw---- 1 root cdrom 21, 6 Jan 6 23:07 /dev/sg6 |
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> > brw-rw---- 1 root cdrom 11, 0 Jan 17 22:28 /dev/sr0 |
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> > -mike |
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> |
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> i dont know why, but it does probe also non-removable disks... it probes |
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> per bus, iirc |
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> |
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> you can try it easily yourself: |
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|
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this is a failure in cdrecord (not that surprising). it aborts after the first |
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EACCES it gets on /dev/sg# instead of continuing on. granting set*id to a |
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binary because they can't be bothered to try the next device is dumb. |
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|
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$ sudo mv /dev/sg[0-5] ~/ |
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$ sudo chmod 755 /usr/bin/cdrecord |
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$ cdrecord -scanbus |
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|
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Cdrecord-ProDVD-ProBD-Clone 3.01a06 (x86_64-unknown-linux-gnu) Copyright (C) |
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1995-2011 Joerg Schilling |
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TOC Type: 1 = CD-ROM |
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Linux sg driver version: 3.5.34 |
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Using libscg version 'schily-0.9'. |
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Using libscg transport code version 'schily-scsi-linux-sg.c-1.95' |
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Driveropts: 'burnfree' |
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SCSI buffer size: 32768 |
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scsibus7: |
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7,0,0 700) 'TSSTcorp' 'CDDVDW SH-S222L ' 'SB03' Removable CD-ROM |
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7,1,0 701) * |
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7,2,0 702) * |
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7,3,0 703) * |
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7,4,0 704) * |
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7,5,0 705) * |
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7,6,0 706) * |
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7,7,0 707) * |
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-mike |