Re: EACCESS vs ENOENT for nonexistent files-within-files

[Hans Reiser <reiser@namesys.com>]

Paul Wagland wrote:

>On Wed 15 Sep 2004 01:41:40 PM CEST, Nikita Danilov wrote:
>  
>
>>evilninja writes:
>> > evil@prinz:/tmp$ touch file.txt
>> > evil@prinz:/tmp$ cat file.txt/.htaccess
>> > cat: file.txt/.htaccess: Not a directory
>> > evil@prinz:/tmp$ chmod +x file.txt
>> > evil@prinz:/tmp$ cat file.txt/.htaccess
>> > cat: file.txt/.htaccess: Not a directory
>>
>>But in reiser4 file.txt _is_ a directory. That's the whole point: it
>>contains other objects inside.
>>    
>>
>
>[...]
>
>  
>
>>This is very simple: do be able to do a lookup one needs +x bit. No +x
>>bit--no lookup. No lookup---impossible to determine exists .htaccess or
>>not.
>>
>>Permission bits determine what operations are possible on
>>object. Letting user to know that .htaccess doesn't exist while
>>permission bits on parent explicitly disable lookups is a security
>>hole.
>>    
>>
>
>I'm sorry to be so blunt on this... but this is just plain dumb. Really. For as
>long as I have known, an executable bit on a file means that you can "execute"
>that file. Now  you try to say, yeah, that, but as well, it means whether or
>not you can access the files attributes?
>
>Seriously. What were you thinking?
>
>Does this mean (for example) that on a sgid file, only the group can see the
>attributes? Even if the file is world readable? Does this really make sense?
>
>Here is the rub... you are breaking the rules of "one object - one purpose".
>Surely this is not how it is meant to be? On a file, the execute bit is meant
>for "can I run this file". On a dir, this bit is for "Can I see inside this
>directory". They do not match!
>
>Paul.
>  
>
Separate bits are needed for the separate purposes.  Nikita, can you 
remind what implementation details delay separating the bits?  I thought 
it was already done, sigh....

Hans