Re: [PATCH 0/2] ima: policy search speedup

From: Kasatkin, Dmitry
Date: Tue Dec 11 2012 - 13:10:04 EST


On Tue, Dec 11, 2012 at 7:55 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Dec 11, 2012 at 9:40 AM, Kasatkin, Dmitry
> <dmitry.kasatkin@xxxxxxxxx> wrote:
>>>
>>> Quite frankly, this seems stupid.
>>
>> What exactly seems stupid here?
>
> What I said. Go back and read it. I gave three reasons. Why do you ask?
>
> I'll give one more reason, but you probably won't read *this* email
> either, will you?
>

No comments. Should I say more here?
Better read further...

>> There are different filesystems which are not checked by IMA/EVM,
>> such as pseudo-filesystems.
>
> Did you read my email?
>
> There are probably *also* individual that aren't checked by IMA/EVM
> even on filesystems that *do* check other files.
>
> No?
>
> And your "pseudo-filesystems" argument is pretty stupid too, since WE
> ALREADY HAVE A FLAG FOR THAT!
>
> Guess where it is? Oh, it's in the place I already mentioned makes
> more sense. Look for S_PRIVATE in inode->i_flags, and IS_PRIVATE() in
> users. It's what the other security models already use to avoid
> bothering calling down to the security layers. The fact that the
> integrity layer bypasses the normal security layer in
> ima_file_check(), for example, is no excuse to then make up totally
> new flags.
>
> So let me repeat: adding a new superblock flag seems STUPID. Why is it
> in a completely different place than all the other flags that we
> already have for these kinds of things? Why should we add a new field,
> when we have existing fields that seem to do exactly this, do it
> better, and are already used?
>

I was suggesting to add a flag for sb->s_flags field.
Al said that he would not like this, because s_flags are mount specific.
One of suggestions in response was to use s_feature flags, because other FSs
would benefit from that as well..

https://lkml.org/lkml/2012/9/19/460


> And don't ask me why without reading this email. OK?

Again, no comments.


>
> Linus
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