Re: [PATCH v7 10/15] platform/x86: dell-smbios: add filtering capability for requests

[Alan Cox]

> Within Linux the security model is that items accessible through this interface
> are only accessible by root.

"root" has not been a security concept in the Linux kernel since about
2.0. If you are relying on file permissions then at best you are using
CAP_SYS_DAC which is too weak for this.

If you are allowing near unchecked communication with a third party
entity that the user doesn't trust too much you should be requiring
CAP_SYS_RAWIO.

In fact it's a fair argument hat if you require CAP_SYS_RAWIO and have a
module option you have to set to allow it that with the module loaded
with say

	insmod dell_smbios factory=1

does even blacklisted stuff then you are ok, because a process with
CAP_SYS_RAWIO has enough power to totally own the machine anyway
including taking over and doing the WMI call itself by hand in user space
or loading its own module.

Alan