[Samba] cli_smb2_dskattr() returning with NT_STATUS_INVALID_NETWORK_RESPONSE with blob length 65535

[Tompkins, Michael]

We have found that in one case we are getting:
        GetInfo Response (0x10)
                ...
                StructureSize: 0x0009
                0000 0000 0000 1000. = Fixed Part Length: 4
                .... .... .... ...1 = Dynamic Part: True
                Blob Offset: 0x00000048
                Blob Length: 65535

In samba-4.7.5/source3/libsmb/cli_smb2_fnum.c, function: cli_smb2_dskattr() we see:

1943    /* getinfo on the returned handle with info_type SMB2_GETINFO_FS (2),
1944       level 3 (SMB_FS_SIZE_INFORMATION). */
1945
1946    status = smb2cli_query_info(cli->conn,
1947                            cli->timeout,
1948                            cli->smb2.session,
1949                            cli->smb2.tcon,
1950                            2, /* in_info_type */
1951                            3, /* in_file_info_class */
1952                            0xFFFF, /* in_max_output_length */
1953                            NULL, /* in_input_buffer */
1954                            0, /* in_additional_info */
1955                            0, /* in_flags */
1956                            ph->fid_persistent,
1957                            ph->fid_volatile,
1958                            frame,
1959                            &outbuf);
1960    if (!NT_STATUS_IS_OK(status)) {
1961            goto fail;
1962    }
1963
1964    /* Parse the reply. */
1965    if (outbuf.length != 24) {
1966            status = NT_STATUS_INVALID_NETWORK_RESPONSE;
1967            goto fail;
1968    }
1969

So we decided to try change it to:

+       if (outbuf.length < 24) {
+              status = NT_STATUS_INVALID_NETWORK_RESPONSE;
+              goto fail;
+       }

And the transfer passed.  This was in 4.7.5 but we see the same logic exists in 4.12.x ... So do you think this is a valid change ? Is 65535 an expected valid return ? Is it indicating something ?  Have you seen other cases where the blob length may not be 24 ? Your feedback would be great appreciated.

Mike