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Re: cygwin potentially corrupting permissions?


On Thu, Sep 24, 2015 at 2:06 PM, Linda Walsh <cygwin@tlinx.org> wrote:
> Greg Freemyer wrote:
>>
>> Linda,
>
>
>> I saved your script as "lsacl.txt".  Then I used "cp lsacl.txt it" to
>> make a copy.
>>
>> The copy is permission denied for reading.  Basic ls -l shows no
>> difference (as expected)
>>
>> $ ls -l lsacl.sh it
>> ----rwx---+ 1 gaf None 1630 Sep 24 12:05 it
>> ----rwx---+ 1 gaf None 1630 Sep 24 12:00 lsacl.sh
>>
>> But your script does show a difference:
>>
>> $ ./lsacl.sh lsacl.sh it
>> [u::---,g::---,g:root:rwx,g:Authenticated
>> Users:rwx,g:SYSTEM:rwx,g:Users:r-x,m:rwx,o:---/] lsacl.sh
>> [u::---,g::r-x,g:root:rwx,g:Authenticated
>> Users:rwx,g:SYSTEM:rwx,g:Users:r-x,m:rwx,o:---/] it
>
> ---
>         Well user 'gaf' (that's you, from the file perms has no access).
>
>         So up front, you are denied before anything happens.

Totally logical, but not accurate. )

I am the owner of both "it" and "lsacl.sh."

For both the user permissions are "---"  (why I don't know.  I created
lsacl.sh by a simple drag and drop out of firefox.)

I can cat out "lsacl.sh", but not "it".

I know "chmod +rw it" gives me access to the file.  The problem is
Windows is creating files with permissions like lsacl.sh routinely on
my system.

Then when I do anything to them in cygwin, the permissions are
modified to block my access.

I first noticed this because I was exporting CSV files from excel,
then editing them with vi from cygwin.

On the first edit, all was good.  After that, I no longer had
permission to access the file.

So, either:

- Windows 7 (on 2 different machines) has started using default
permissions that are bad on their face

- cygwin is not properly maintaining the permissions when it manipulates a file

Either way, I would really like a solution that doesn't involve a
manual chmod for every file I create via the normal Windows interface
and which I want to work with it in cygwin.

Greg


> lsacl is the embedded acl (the '+') at the end of the file perms
>
> u::--- =  user seen by 'ls -l' has no access, g::--- =  group seen by 'ls -l
> has no access
> g:root:rwx = group root has read/write/execute access
> g:Authenticated Users:rwx == group consisting of Authenticated Users...
> (after you login or provide credentials).
> m:rwx  m = a maximum allowed privs 'mask' for user/groups other
>         than owner, but since all bits are turned on, it has no limiting
>         effect
> o:---  = other has no access
>
> So the main take-away is that since your 'user' has no access, pretty much
> everything else is ignored.
>
> From the mode-bits+acl, amost anyone in the groups:
> root, Authenticated Users,SYSTEM, or Users, ***except** User 'gaf' (you)
> should have access...
>
> you might try 1) chmod u+rwx file ...
> then look at both mode+acl... if you have no access
> and acl still says u::---, then nuke the acl or modify it with "setfacl"
> (setfacl --help)...
>
>>
>> We seem to travel the same mailing lists.  This is my first time to
>> cygwin's.
>>
> ----
> Yeah... I wondered about that -- my Tbird tried to change my
> reply addr to suse(at)tlinx based on you being the 1st address I typed
> in... ;-)

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