[PATCH 0/3] Some O_PATH fixes

Ken Brown kbrown@cornell.edu
Thu Jan 30 17:01:00 GMT 2020

On 1/29/2020 9:22 AM, Corinna Vinschen wrote:
> On Jan 29 10:52, Corinna Vinschen wrote:
>> On Jan 29 03:08, Ken Brown wrote:
>>> On 1/28/2020 3:48 PM, Ken Brown wrote:
>>>> On 1/28/2020 2:01 PM, Ken Brown wrote:
>>>>> On 1/28/2020 12:06 PM, Corinna Vinschen wrote:
>>>>>> As outlined on IRC, I found a problem with the ACLs created on new
>>>>>> FIFOs and frixed that (I think).  However, Cygwin doesn't actually
>>>>>> return the real permissions in stat(), only the constant perms 0666,
>>>>>> kind of like for symlinks.  I didn't have time to look into that yet,
>>>>>> but it would be great if we could fix that, too.
>>>>> I'll take a look if you don't get to it first.
>>>> Two quick thoughts, and then I won't have time to think about this any more
>>>> until tomorrow:
>>>> First, I wonder why in fstat_fs we're not using the stat handle (i.e., pc.handle()).
>>> Ignore this.  I was confused.
>>>> Second, in the call to get_file_attribute in fstat_helper
>>>> (fhandler_disk_file.cc:478), why do we set the first argument to NULL instead of
>>>> using our handle?
>> The handle is a pipe handle, not the file handle, and the permissions
>> on the pipe handle were not reflecting the permissions on the file.
>> The NULL pointer was trying to make sure that the file gets opened
>> for fetching the security descriptor in get_file_sd().
> I pushed a fix for the permission problem, but I didn't touch the
> get_file_attribute() call in fstat_helper.  If you think this can
> be further streamlined, go ahead.

AFAICT, the handle returned by get_stat_handle() should always be pc.handle(), 
not a pipe handle.  Patch on the way.


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