Re: [PATCH 0/3] SG_IO command filtering via sysfs

[Christoph Hellwig]

On Sun, Nov 11, 2018 at 08:42:42AM -0500, Theodore Y. Ts'o wrote:
> It really depends on the security model being used on a particular
> system.  I can easily imagine scenarios where userspace is allowed
> full access to the device with respect to read/write/open, but the
> security model doesn't want to allow access to various SCSI commands
> such as firmware upload commands, TCG commads, the
> soon-to-be-standardized Zone Activation Commands (which allow dynamic
> conversion of HDD recording modes between CMR and SMR), etc.

Well, that's what we have the security_file_ioctl() LSM hook for so that
your security model can arbitrate access to ioctls.