Re: bug in [ -f file ] test

[Reuti]

> Am 27.07.2016 um 18:55 schrieb László Házy <hazy_l@yahoo.com>:
> 
> Here it goes. Note that the second command you asked for returns the same as 
> the "file" entry in the first command. Thanks.

Yeah, I meant:

$ ls -Zd /home/user1

to show the entry of the directory itself, not its content. - Reuti


> [user1]$ ls -Z /home/user1
> unconfined_u:object_r:user_home_t:s0 Desktop 
> unconfined_u:object_r:user_home_t:s0 Documents 
> unconfined_u:object_r:user_home_t:s0 Downloads 
> unconfined_u:object_r:user_home_t:s0 file 
> unconfined_u:object_r:audio_home_t:s0 Music 
> unconfined_u:object_r:user_home_t:s0 Pictures 
> unconfined_u:object_r:user_home_t:s0 Public 
> unconfined_u:object_r:user_home_t:s0 Templates 
> unconfined_u:object_r:user_home_t:s0 Videos
> 
> 
> 
> 
> On Wed, 2016-07-27 at 18:28 +0200, Reuti wrote:
>>> 
>>> Am 27.07.2016 um 18:13 schrieb László Házy <
>>> hazy_l@yahoo.com
>>> >:
>>> 
>>> Yes, SELinux is active.
>>> 
>> 
>> 
>> Fine.
>> 
>> Can you please provide:
>> 
>> $ ls -Z /home/user1
>> $ ls -Z /home/user1/file
>> 
>> -- Reuti
>> 
>> 
>> 
>>> 
>>> On Wed, 2016-07-27 at 17:55 +0200, Reuti wrote:
>>> 
>>>> 
>>>>> 
>>>>> 
>>>>> Am 27.07.2016 um 17:36 schrieb László Házy <
>>>>> 
>>>>> hazy_l@yahoo.com
>>>>>> 
>>>>>> :
>>>>>> 
>>>>> 
>>>>> 
>>>>> Yes, user2 has rx access to /home/user1. This is done by the first 
>>>>> command in the list of commands, namely: "[user1]$ chmod g+rx 
>>>>> /home/user1". The two users are part of the same group.
>>>>> 
>>>>> An even more troublesome variation, involving root, is the following:
>>>>> 
>>>>> [user1]$ touch file; ls -l file
>>>>> -rw-r--r--. 1 user1 users    0 Jul 26 15:24 file
>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> 
>>>> The dot at the end means SELinux ACL IIRC - are you running SELinux?
>>>> 
>>>> -- Reuti
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> 
>>>>> 
>>>>> [user1]$ ln -s /home/user1/file /var/tmp/link
>>>>> [user1]$ ls -l /var/tmp/link
>>>>> lrwxrwxrwx. 1 user1 users 17 Jul 26 15:26 /var/tmp/link -> 
>>>>> /home/user1/file
>>>>> 
>>>>> [user1]$ [[ -f /var/tmp/link ]]; echo $?
>>>>> 0
>>>>> 
>>>>> [user1]$ su 
>>>>> [root]$ [[ -f /var/tmp/link ]]; echo $?
>>>>> 1
>>>>> 
>>>>> 
>>>>> On Tue, 2016-07-26 at 23:26 +0200, Reuti wrote:
>>>>> 
>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Am 26.07.2016 um 23:07 schrieb László Házy:
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> Hmm, interesting. I can reproduce your results. Thanks.
>>>>>>> However, note the following:
>>>>>>> 
>>>>>>> [user1]$ chmod g+rx /home/user1
>>>>>>> [user1]$ touch file; ls -l file
>>>>>>> -rw-r--r--. 1 user1 users    0 Jul 26 15:24 file
>>>>>>> 
>>>>>>> [user1]$ su user2 -c "ln -s /home/user1/file /var/tmp/link"
>>>>>>> [user1]$ ls -l /var/tmp/link
>>>>>>> lrwxrwxrwx. 1 user2 users 17 Jul 26 15:26 /var/tmp/link -> 
>>>>>>> /home/user1/file
>>>>>>> 
>>>>>>> [user1]$ [[ -f /var/tmp/link ]]; echo $?
>>>>>>> 1
>>>>>>> 
>>>>>>> [user1]$ su user2
>>>>>>> [user2]$ [[ -f /var/tmp/link ]]; echo $?
>>>>>>> 0
>>>>>>> 
>>>>>>> Something does not add up.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Does user2 have rx access to /home/user1?
>>>>>> 
>>>>>> -- Reuti
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> From experimenting, it appears that only the user who created the 
>>>>>>> symlink will get true for the file test.
>>>>>>> 
>>>>>>> Thank you.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> On Tue, 2016-07-26 at 15:06 -0400, Grisha Levit wrote:
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Are you sure "file" is a link to an actual file, not, say, a directory?
>>>>>>>> 
>>>>>>>> $ rpm -q bash; echo $BASH_VERSION; cat /etc/redhat-release
>>>>>>>> bash-4.3.42-3.fc23.x86_64
>>>>>>>> 4.3.42(1)-release
>>>>>>>> Fedora release 23 (Twenty Three)
>>>>>>>> 
>>>>>>>> $ touch file; ln -s file link; [[ -f link ]]; echo $?
>>>>>>>> 0
>>>>>>>> 
>>>>>>>> On Tue, Jul 26, 2016 at 12:58 PM, László Házy <
>>>>>>>> 
>>>>>>>> 
>>>>>>>> hazy_l@yahoo.com
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> wrote:
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> I am running bash 4.3.42-3 on Fedore Core 23.
>>>>>>>>> 
>>>>>>>>> I noticed that the [ -f file ] test returns false if "file" is a 
>>>>>>>>> symlink. Given the intended behavior (from a long time ago), this is 
>>>>>>>>> wrong as the symlinks are supposed to be followed. It certainly 
>>>>>>>>> brakes functionality in certain existing software.
>>>>>>>>> 
>>>>>>>>> Has the default behavior been changed somewhere along the time line 
>>>>>>>>> and I am not aware of it?
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
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