Vendor specific SCSI opcodes

Vendor specific SCSI opcodes

[Mathieu Fluhr]

Hello all

I have a problem when using vendor-specific SCSI opcodes with the
ide-cdrom drive. Unless I run the CDROM_SEND_PACKET ioctl as root, I am
getting an error.... plus a kernel warning: 
  Aug 10 12:09:08 localhost kernel: scsi: unknown opcode 0xfa

(..and there is not only 0xfa ad opcode ;-)

As far as I have understood the kernel source code, the problem seems to
be related to the verify_command() introduced in 2.6.8. The thing is
that all these vendor-specific opcodes are not inside the 'cmd_type',
and so not 'safe'.
Nice thing is that when I use exactly the same device over an IDE-to-USB
bridge, it is working like a charm ;-)

So is there a way to bypass this command verification and to let the
program work without launching it as root user ?

Best Regards,
Mathieu

Re: Vendor specific SCSI opcodes

[Alan Cox]

On Llu, 2005-08-15 at 15:34 +0200, Mathieu Fluhr wrote:
> So is there a way to bypass this command verification and to let the
> program work without launching it as root user ?

If there was what would be the point in having a root user. The vendor
specific commands include functionality like "erase firmware" that
simply isn't appropriate to give to unprivileged applications.