samba - Dec 2020 - Strange logs: check_usershare_stat: file /var/lib/samba/usershares/ owned by uid 0 is not a regular file

On 01/12/2020 22:35, Jeremy Allison wrote:
> On Tue, Dec 01, 2020 at 10:32:32PM +0000, Rowland penny via samba wrote:
>> On 01/12/2020 22:23, Andrew Bartlett wrote:
>>> On Tue, 2020-12-01 at 14:19 -0800, Jeremy Allison via samba wrote:
>>>> On Tue, Dec 01, 2020 at 10:08:34PM +0000, Rowland penny via
samba
>>>> wrote:
>>>>
>>>>> could this have anything to do with it:
>>>>>
>>>>> 4.12.0
>>>>> Default: usershare max shares = 0
>>>>>
>>>>> 4.13.2
>>>>> Default: usershare max shares = 100
>>>> Good catch. Yes, that would cause
>>>> the usershare load path to be executed
>>>> now whereas it wasn't before.
>>> Even if we didn't change the default, Debian does.? But the
code should
>>> work of course, be it enabled by default or by the administrator...
>>>
>>> Andrew Bartlett
>>
>> Yes, it is Debian, just found this out by downloading the relevant 
>> file from Louis's repo, they appear to be turning usershares on 
>> without actually setting up usershares. I would suggest the code 
>> would work if usershares were actually set up correctly, I have used 
>> usershares in the past and I don't remember syslog getting spammed.
>
> Well I still don't know why he's seeing syslog spam from
> an empty usershare directory. That shouldn't happen even
> if the code is going down the usershare path now.
He is not alone, I didn't know I had a problem until I checked syslog, 
my lines are bit different:

Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.671948,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. Permission denied
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.676259,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.680641,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.687020,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.689004,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.797171,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.799966,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.802785,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.805444,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:14:26 raspberrypi smbd[21036]: [2020/12/01 09:14:26.891225,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:26 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. Permission denied
Dec? 1 09:14:27 raspberrypi smbd[21036]: [2020/12/01 09:14:27.007528,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:27 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:14:27 raspberrypi smbd[21036]: [2020/12/01 09:14:27.011952,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:27 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:14:27 raspberrypi smbd[21036]: [2020/12/01 09:14:27.019275,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:27 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:14:27 raspberrypi smbd[21036]: [2020/12/01 09:14:27.023257,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:14:27 raspberrypi smbd[21036]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.602306,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. Permission denied
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.606630,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.609381,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.613345,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.616161,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.628951,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.631745,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.634465,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:32 raspberrypi smbd[21090]: [2020/12/01 09:32:32.638399,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:32 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/profiles.v6 failed. No such file or directory
Dec? 1 09:32:33 raspberrypi smbd[21090]: [2020/12/01 09:32:33.136664,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:33 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. Permission denied
Dec? 1 09:32:33 raspberrypi smbd[21090]: [2020/12/01 09:32:33.141394,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:33 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:32:33 raspberrypi smbd[21090]: [2020/12/01 09:32:33.145025,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:33 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:32:33 raspberrypi smbd[21090]: [2020/12/01 09:32:33.148401,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:33 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory
Dec? 1 09:32:33 raspberrypi smbd[21090]: [2020/12/01 09:32:33.152002,? 
0] ../../source3/param/loadparm.c:3422(process_usershare_file)
Dec? 1 09:32:33 raspberrypi smbd[21090]:?? process_usershare_file: stat 
of /var/lib/samba/usershares/sharename failed. No such file or directory

The messages are quite true, the files do not exist, this is on 4.13.2 
running as a Unix domain member. I cannot see anything in git that has 
changed that could cause this and do not remember seeing anything in 
syslog like this before. in this instance, they are only warnings, so 
why are they debug 0 ?

Rowland

On Tue, Dec 01, 2020 at 10:46:05PM +0000, Rowland penny via samba
wrote:
>
>He is not alone, I didn't know I had a problem until I checked syslog, 
>my lines are bit different:
>
>Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.671948,? 
>0] ../../source3/param/loadparm.c:3422(process_usershare_file)
>Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: 
>stat of /var/lib/samba/usershares/profiles.v6 failed. Permission 
>denied
The only thing inside /var/lib/samba/usershares/
should be usershare file definitions, owned by the
user who created them.

What is: /var/lib/samba/usershares/profiles.v6
and why is it there ?
>The messages are quite true, the files do not exist, this is on 4.13.2 
>running as a Unix domain member. I cannot see anything in git that has 
>changed that could cause this and do not remember seeing anything in 
>syslog like this before. in this instance, they are only warnings, so 
>why are they debug 0 ?
I chose debug zero because usershare files are *dangerous* if misconfigured.
Might grant access that should not be allowed.

Default value for max usershares as shipped by us should
be zero. Let distro's change that if they wish.

If there are strange files in /var/lib/samba/usershares you need
to do something about it and remove them :-).

That's why the debug 0. But why are they there and what
is in those files ?

On Tue, Dec 01, 2020 at 10:46:05PM +0000, Rowland penny via samba
wrote:
>On 01/12/2020 22:35, Jeremy Allison wrote:
>>On Tue, Dec 01, 2020 at 10:32:32PM +0000, Rowland penny via samba wrote:
>>>On 01/12/2020 22:23, Andrew Bartlett wrote:
>>>>On Tue, 2020-12-01 at 14:19 -0800, Jeremy Allison via samba
wrote:
>>>>>On Tue, Dec 01, 2020 at 10:08:34PM +0000, Rowland penny via
samba
>>>>>wrote:
>>>>>
>>>>>>could this have anything to do with it:
>>>>>>
>>>>>>4.12.0
>>>>>>Default: usershare max shares = 0
>>>>>>
>>>>>>4.13.2
>>>>>>Default: usershare max shares = 100
>>>>>Good catch. Yes, that would cause
>>>>>the usershare load path to be executed
>>>>>now whereas it wasn't before.
>>>>Even if we didn't change the default, Debian does.? But the
code should
>>>>work of course, be it enabled by default or by the
administrator...
>>>>
>>>>Andrew Bartlett
>>>
>>>Yes, it is Debian, just found this out by downloading the relevant 
>>>file from Louis's repo, they appear to be turning usershares on 
>>>without actually setting up usershares. I would suggest the code 
>>>would work if usershares were actually set up correctly, I have 
>>>used usershares in the past and I don't remember syslog getting 
>>>spammed.
>>
>>Well I still don't know why he's seeing syslog spam from
>>an empty usershare directory. That shouldn't happen even
>>if the code is going down the usershare path now.
>
>He is not alone, I didn't know I had a problem until I checked syslog, 
>my lines are bit different:
>
>Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.671948,? 
>0] ../../source3/param/loadparm.c:3422(process_usershare_file)
>Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: 
>stat of /var/lib/samba/usershares/profiles.v6 failed. Permission 
>denied
Hang on a minute - the above says "Permission denied"
for "/var/lib/samba/usershares/profiles.v6"

That means the directory scanner found something
inside:

/var/lib/samba/usershares
>Dec? 1 09:14:25 raspberrypi smbd[21036]: [2020/12/01 09:14:25.676259,? 
>0] ../../source3/param/loadparm.c:3422(process_usershare_file)
>Dec? 1 09:14:25 raspberrypi smbd[21036]:?? process_usershare_file: 
>stat of /var/lib/samba/usershares/profiles.v6 failed. No such file or 
>directory
Now it says "No such file or directory" for
"/var/lib/samba/usershares/profiles.v6"

Which is right ?