[linux-cifs-client] massive problems with unix extensions and possible fix

[Stefan Rompf]

Hi,

I tried to use cifsfs 1.24 to connect to a samba 3.0.7 server using unix 
extensions. Most file accesses worked, however, when compiling a company 
internal software, I experienced all kinds of weird locks, connection losses 
etc. I've attached an ethereal dump of the SMB_SET_FILE_UNIX_BASIC packet 
before remote closed the connection clearly with a FIN.

As you can see, the cifs client does not initialize the structure, it just 
sets some fields. Now samba 3.0.7 tries to use the timestamp, cannot convert 
it and this seems to be the failure cause.

This patch helped:

*** cifssmb.c.orig      Tue Nov 23 16:05:35 2004
--- cifssmb.c   Wed Dec  1 11:31:15 2004
*************** setPermsRetry:
*** 3316,3321 ****
--- 3316,3322 ----
        data_offset =
            (FILE_UNIX_BASIC_INFO *) ((char *) &pSMB->hdr.Protocol +
                                      offset);
+       memset(data_offset, 0, sizeof(FILE_UNIX_BASIC_INFO));
        pSMB->DataOffset = cpu_to_le16(offset);
        pSMB->ParameterOffset = cpu_to_le16(param_offset);
        pSMB->SetupCount = 1;

Comments? I think memsets like these are also missing in other places of 
cifs-client. To me it seems quite risky to send unitialized structures over 
the network hoping that some known server version does not process them.

Stefan
-------------- next part --------------
SMB (Server Message Block Protocol)
    SMB Header
    Trans2 Request (0x32)
        Word Count (WCT): 15
        Total Parameter Count: 180
        Total Data Count: 100
        Max Parameter Count: 2
        Max Data Count: 1000
        Max Setup Count: 0
        Reserved: 00
        Flags: 0x0000
        Timeout: Return immediately (0)
        Reserved: 0000
        Parameter Count: 180
        Parameter Offset: 68
        Data Count: 100
        Data Offset: 248
        Setup Count: 1
        Reserved: 00
        Subcommand: SET_PATH_INFO (0x0006)
        Byte Count (BCC): 283
        Padding: 000000
        SET_PATH_INFO Parameters
            Level of Interest: Set File Unix Basic (512)
            Reserved: 00000000
            File Name: \1234\12345678\12345678912345678912345678912345678912345678\12345678912345678912345678
        SET_PATH_INFO Data
            File size: 8315172550388744192
            Number of bytes: 6874592421672660480
            Last status change: Time can't be converted
            Last access: Time can't be converted
            Last modification: Time can't be converted
            UID: 18446744073709551615
            GID: 18446744073709551615
            File type: File (0)
            Major device: 0x0000000000000000
            Minor device: 0x0000000000000000
            Unique ID: 0x666e6963616d5f67
            File permissions: 0x00000000000081ed
            Num links: 8241419596970943534