From: Meng Xu
Date: Tue, 19 Sep 2017 14:52:58 -0400
> In isdn_ppp_write(), the header (i.e., protobuf) of the buffer is fetched
> twice from userspace. The first fetch is used to peek at the protocol
> of the message and reset the huptimer if necessary; while the second
> fetch copies in the whol
In isdn_ppp_write(), the header (i.e., protobuf) of the buffer is fetched
twice from userspace. The first fetch is used to peek at the protocol
of the message and reset the huptimer if necessary; while the second
fetch copies in the whole buffer. However, given that buf resides in
userspace memory,