After we are done with the tty buffer, zero it out.
Reported-by: aszlig <aszlig@nix.build>
Tested-by: Milan Broz <gmazyland@gmail.com>
Tested-by: Daniel Zatovic <daniel.zatovic@gmail.com>
Tested-by: aszlig <aszlig@nix.build>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 {
        unsigned char *p = char_buf_ptr(head, head->read);
        char          *f = NULL;
+       int n;
 
        if (~head->flags & TTYB_NORMAL)
                f = flag_buf_ptr(head, head->read);
 
-       return port->client_ops->receive_buf(port, p, f, count);
+       n = port->client_ops->receive_buf(port, p, f, count);
+       if (n > 0)
+               memset(p, 0, n);
+       return n;
 }
 
 /**