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From: (Eric W. Biederman)
To: James Morris <>
Cc: Mimi Zohar <>,,,, David Howells <>,
	"Luis R . Rodriguez" <>,, Andres Rodriguez <>,
	Greg Kroah-Hartman <>,
	Ard Biesheuvel <>,
	Kees Cook <>,
	Casey Schaufler <>
Subject: Re: [PATCH v3 1/7] security: rename security_kernel_read_file() hook
Date: Fri, 25 May 2018 14:51:00 -0500	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <> (James Morris's message of "Sat, 26 May 2018 01:41:52 +1000 (AEST)")

James Morris <> writes:

> On Thu, 24 May 2018, Eric W. Biederman wrote:
>> Below is where I suggest you start on sorting out these security hooks.
>> - Adding a security_kernel_arg to catch when you want to allow/deny the
>>   use of an argument to a syscall.  What security_kernel_file_read and
>>   security_kernel_file_post_read have been abused for.
> NAK. This abstraction is too semantically weak.
> LSM hooks need to map to stronger semantics so we can reason about what 
> the hook and the policy is supposed to be mediating.

I will take that as an extremely weak nack as all I did was expose the
existing code and what the code is currently doing.  I don't see how you
can NAK what is already being merged and used.

I will be happy to see a better proposal.

The best I can see is to take each and every syscall that my patch
is calling syscall_kernel_arg and make it it's own hook without an
enumeration.  I did not see any real duplication between the cases in my
enumeration so I don't think that will be a problem.  Maybe a bit of a
challenge for loadpin but otherwise not.

Thank you in this for understanding why I am having problems with the
current hook.


  reply	other threads:[~2018-05-25 19:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-24 11:09 [PATCH v3 0/7] kexec/firmware: support system wide policy requiring signatures Mimi Zohar
2018-05-24 11:09 ` [PATCH v3 1/7] security: rename security_kernel_read_file() hook Mimi Zohar
2018-05-24 20:49   ` Eric W. Biederman
2018-05-24 23:29     ` Mimi Zohar
2018-05-25 12:22     ` Mimi Zohar
2018-05-25 15:41     ` James Morris
2018-05-25 19:51       ` Eric W. Biederman [this message]
2018-05-29 20:32         ` James Morris
2018-05-29 21:10           ` Eric W. Biederman
2018-05-24 11:09 ` [PATCH v3 2/7] kexec: add call to LSM hook in original kexec_load syscall Mimi Zohar
2018-05-24 20:50   ` Eric W. Biederman
2018-05-24 11:09 ` [PATCH v3 3/7] ima: based on policy require signed kexec kernel images Mimi Zohar
2018-05-24 11:09 ` [PATCH v3 4/7] firmware: add call to LSM hook before firmware sysfs fallback Mimi Zohar
2018-05-24 11:09 ` [PATCH v3 5/7] ima: based on policy require signed firmware (sysfs fallback) Mimi Zohar
2018-05-24 11:09 ` [PATCH v3 6/7] ima: add build time policy Mimi Zohar
2018-05-24 11:09 ` [RFC PATCH v3 7/7] ima: based on policy prevent loading firmware (pre-allocated buffer) Mimi Zohar

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