samba - May 2025 - DCERPC_NCA_S_OP_RNG_ERROR?

Hi!

I'm seeing quite a lot of messages like this one:

  [2024/06/07 06:52:47.259003,  1]\
   source3/rpc_client/cli_pipe.c:550(cli_pipe_validate_current_pdu)
  source3/rpc_client/cli_pipe.c:550: \
   RPC fault code DCERPC_NCA_S_OP_RNG_ERROR received from host tsrv!

in log.wb-TSRV file on a regular domain member server acting as a
file server.

This happens with at least samba versions 4.21 and 4.22.  Domain
is handled by samba or by windows, - it doesn't matter.

The prob is that there seem to be no places in samba source where
such error code can be generated to begin with?

What's the problem here?

Thanks,

/mjt

On 23.05.2025 12:23, Michael Tokarev via samba wrote:
> Hi!
> 
> I'm seeing quite a lot of messages like this one:
> 
>  ?[2024/06/07 06:52:47.259003,? 1]\
>  ? source3/rpc_client/cli_pipe.c:550(cli_pipe_validate_current_pdu)
>  ?source3/rpc_client/cli_pipe.c:550: \
>  ? RPC fault code DCERPC_NCA_S_OP_RNG_ERROR received from host tsrv!
> 
> in log.wb-TSRV file on a regular domain member server acting as a
> file server.
> 
> This happens with at least samba versions 4.21 and 4.22.? Domain
> is handled by samba or by windows, - it doesn't matter.
It looks like this logging only occurs with samba 4.22[.1],
not with 4.21.

FWIW, I had to downgrade 4.22 to 4.21 due to some weird issue
with windows clients - unfortunately it only happened on a single
production server and I can't reproduce it on a test environment.
Dunno if the logging from this message is related or not, though.
> The prob is that there seem to be no places in samba source where
> such error code can be generated to begin with?
> 
> What's the problem here?
> 
> Thanks,
> 
> /mjt
>