linux-kernel - Re: [netfs/cifs - Linux 6.14] loop on file cat + file copy when files are on CIFS share

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <e63e7c7ec32e3014eb758fd6f8679f93@3xo.fr>
Date: Thu, 17 Apr 2025 12:10:20 +0200
From: Nicolas Baranger <nicolas.baranger@....fr>
To: Paulo Alcantara <pc@...guebit.com>
Cc: Christoph Hellwig <hch@...radead.org>, hch@....de, David Howells
 <dhowells@...hat.com>, netfs@...ts.linux.dev, linux-cifs@...r.kernel.org,
 linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, Steve French
 <smfrench@...il.com>, Jeff Layton <jlayton@...nel.org>, Christian Brauner
 <brauner@...nel.org>
Subject: Re: [netfs/cifs - Linux 6.14] loop on file cat + file copy when files
 are on CIFS share

Hi Paulo

Resending this mail with content-type: text, sorry !

Thanks again for answer and help, it's good to hear you're back to 
health.

> Thanks for the trace.  I was finally able to reproduce your issue and 
> will provide you with a fix soon.

Perfect... And thanks !

If you need more traces or details on (both?) issues :

- 1) infinite loop issue during 'cat' or 'copy' since Linux 6.14.0

- 2) (don't know if it's related) the very high number of several bytes 
TCP packets transmitted in SMB transaction (more than a hundred) for a 5 
bytes file transfert under Linux 6.13.8

Do not hesitate to ask, I would be happy to help.

Kind regards
Nicolas




Le 2025-04-15 20:28, Paulo Alcantara a écrit :

> Hi Nicolas,
> 
> Sorry for the delay as I've got busy with some downstream work.
> 
> Nicolas Baranger <nicolas.baranger@....fr> writes:
> 
> I'll look into it as soon as I recover from my illness. Hope you're 
> doing better

I'm fully recovered now, thanks :-)

> I had to rollback to linux 6.13.8 to be able to use the SMB share and
> here is what I constat
> (don't know if it's a normal behavior but if yes, SMB seems to be a 
> very
> very unefficient protocol)
> 
> I think the issue can be buffer related:
> On Linux 6.13.8 the copy and cat of the 5 bytes 'toto' file containing
> only ascii string 'toto' is working fine but here is what I capture 
> with
> tcpdump during transfert of toto file:
> https://xba.soartist.net/t6.pcap
> 131 tcp packets to transfer a 5 byte file...
> Isn't there a problem ?
> Openning the pcap file with wireshark show a lot of lines:
> 25    0.005576    10.0.10.100    10.0.10.25    SMB2    1071    Read 
> Response, Error:
> STATUS_END_OF_FILE
> It seems that those lines appears after the 5 bytes 'toto' file had 
> been
> transferred, and it continue until the last ACK recieved

Thanks for the trace.  I was finally able to reproduce your issue and
will provide you with a fix soon.