Messages in this thread | | | Date | Fri, 13 Oct 2017 15:18:32 +0100 | From | Alan Cox <> | Subject | Re: [PATCH v7 10/15] platform/x86: dell-smbios: add filtering capability for requests |
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> 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
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