Re: [PATCH] isdn: eicon: fix a missing-check bug

[David Miller]

From: Wenwen Wang <wang6495@xxxxxxx>
Date: Sat,  5 May 2018 14:32:46 -0500

> To avoid such issues, this patch adds a check after the second copy in the
> function diva_xdi_write(). If the adapter number is not equal to the one
> obtained in the first copy, (-4) will be returned to divas_write(), which
> will then return an error code -EINVAL.

Better fix is to copy the msg header once into an on-stack buffer supplied
by diva_write() to diva_xdi_open_adapter(), which is then passed on to
diva_xdi_write() with an adjusted src pointer and length.