ksmbd: fix malformed unsupported smb1 negotiate response

When mounting with vers=1.0, ksmbd should return unsupported smb1
negotiate response. But this response is malformed.

[ 6010.586702] CIFS: VFS: Bad protocol string signature header 0x25000000
[ 6010.586708] 00000000: 25000000 25000000 424d53ff 00000072  ...%...%.SMBr...
[ 6010.586711] 00000010: c8408000 00000000 00000000 00000000  ..@.............
[ 6010.586713] 00000020: 00 00 b9 32 00 00 01 00 01                  ...2.....

Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: namjaejeon

fs/smb/server/smb_common.c

@@ -576,7 +576,7 @@ static int smb_handle_negotiate(struct ksmbd_work *work)
 
 	ksmbd_debug(SMB, "Unsupported SMB1 protocol\n");
 
-	if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp,
+	if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp + 4,
 			      sizeof(struct smb_negotiate_rsp) - 4))
 		return -ENOMEM;