On Fri, 21 Aug 2015 13:57:48 -0500, Paul Gilmartin <[email protected]> wrote:

>On Fri, 21 Aug 2015 13:04:47 -0500, Mark Zelden wrote:
>
>>>
>>>(And long ago, MVS-OE mentioned "charcase lower" as a preventive.)
>>> 
>I believe this was not in the original design, but provided at a later release
>in order to forestall the DoS exposure.
>
>>>Suppose you have "/u/mzelden".  While it's unmounted I do "cd /u/MZelden".
>>>Automount issues (something like) an ENQ EXC on MZELDEN.TPLEX.ZFS.
>>>While that's in effect you can't mount "/u/mzelden".  Not a DoS of your
>>>entire system, just of your HOME.  (At least this applied to HFS; zFS
>>>might be different.)
>>
>>So, OMVS / ZFS address spaces have the access and it gets mounted 
>>in a microsecond on my very fast z13 with flash disk.   :-) 
>> 
>Not for only a microsecond, but for at least as long as it takes to time
>out and dismount.  And if I can "cd /u/MZelden", for as long as I tarry
>there.  But that requires that I have at least search authority on the
>directory.
>
>>But seriously, where's the exposure?
>>
>I believe IBM covered it because they perceived it.  Can you try "cd 
>/u/MZelden"
>and observe the result?
>

SY01:MZELDEN:/u/mzelden:$ cd /u/MZelden     
cd: /u/MZelden: EDC5121I Invalid argument.  
SY01:MZELDEN:/u/mzelden:$   

Regards,

Mark
--
Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS
ITIL v3 Foundation Certified
mailto:[email protected]
Mark's MVS Utilities: http://www.mzelden.com/mvsutil.html
Systems Programming expert at http://search390.techtarget.com/ateExperts/
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