VERY SERIOUS smbclient problems w/samba 2.0.*

[James Delahanty]

All,

With the belief that, "given enough eyes all bugs are shallow", I submit
the following to the list.  I had sent a shorter version to samba-bugs
last week, but, given the nature of this problem, I think everyone needs
to check this on their own systems.

Overview:
Pulling files from an NT 4.0 machine to a RedHat 5.0 linux box using
2.0.3 or 2.0.4b smbclient *consistently* results in randomly corrupt
files, with no error message to indicate internal file corruption.  We
are able to recreate this problem on all manners of servers and
workstations running NT 4.0, and all manner of linux boxen running
kernels 2.2.4 & 2.2.9.  Although this subset of servers/clients is far
from global, we feel that the nature of the error is such that it
demonstrates a serious problem with smbclient in these versions.  We're
also able to show that smbclient 1.9.18p10 does not demonstrate this
flaw.

Conclusion:
If you use smbclient or smbtar, test your setup using the method
outlined below.  If you can demonstrate the same problem, use the
smbclient 1.9.18p10 binary until a fix is found -- do not trust any
backups of files made using smbclient/smbtar versions 2.0.*

Testing methodology:
A 240 MB directory consisting of 459 files and 51 sub directories,
located on an NT server (nts001) was chosen for the test.  This
directory contains static, archived, reference files.  This directory
was given it's own share (smbtest).  Two directories on the linux server
are created (/var/smbtest1, and /var/smbtest2).  The following set of
commands is executed:

    cd /var/smbtest1
    smbclient \\\\nts001\\smbtest <password> -U administrator -W NT_NET
    smb: \> recurse
    smb: \> prompt
    smb: \> mget *
    smb: \> exit

    cd /var/smbtest2
    smbclient \\\\nts001\\smbtest <password> -U administrator -W NT_NET
    smb: \> recurse
    smb: \> prompt
    smb: \> mget *
    smb: \> exit

    diff -r /var/smbtest1 /var/smbtest2

In every case, using 2.0.3 and 2.0.4b, several (20 to 50) files are
found to be different.  The procedure would indicate that all files
should be identical.  Although no errors appear during the transfer
process, and file sizes are identical, contents of affected files are
radically different.  We've been able to demonstrate this happening on
directories containing as few as 23 files, 20 MB.

Tests using smbclient binary from samba 1.9.18p10 indicate that the
1.9.18p10 version of smbclient does not demonstrate this flaw.

Our Setups:
Dual PII-450 \ Linux kernel 2.2.9, gcc 2.7.2.3, Intel NIC
Dual PII-233 \ Linux kernel 2.2.9, gcc 2.7.2.3, Intel NIC
Dual P-133 \ Linux kernel 2.0.36, gcc 2.7.2.3, Intel NIC
P-233 \ Linux kernel 2.0.36, gcc 2.7.2.3, 3Com NIC
Dual PII-233, NT 4.0 Server, SP3, Intel NIC
K6-2 300, NT 4.0 Workstation, SP4, 3Com NIC
Dual PPro-180, NT 4.0 Server, SP3, Intel NIC

TO WHOEVER MAINTAINS SMBCLIENT:
I can send anything you'd like to see, with regards to log files, etc.
Contact me if you need more information -- I'm glad to help in any way
that I can.

Sincerely,

Jim Delahanty - jimd at gie.com
Sr. Systems Analyst
Gulf Interstate Engineering