Re: [PATCH net v2] sctp: fix copying more bytes than expected in sctp_add_bind_addr

From: David Miller
Date: Tue Mar 08 2016 - 15:05:35 EST

From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Date: Tue, 8 Mar 2016 10:34:28 -0300

> Dmitry reported that sctp_add_bind_addr may read more bytes than
> expected in case the parameter is a IPv4 addr supplied by the user
> through calls such as sctp_bindx_add(), because it always copies
> sizeof(union sctp_addr) while the buffer may be just a struct
> sockaddr_in, which is smaller.
> This patch then fixes it by limiting the memcpy to the min between the
> union size and a (new parameter) provided addr size. Where possible this
> parameter still is the size of that union, except for reading from
> user-provided buffers, which then it accounts for protocol type.
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Tested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>

Applied, thanks.