isisd: don't overrun list of protocols

isisd currently has a list of supported protocols as a fixed array of
size 4.  this can be overran, leading to an overwrite of the ipv4_addrs
pointer.

  * isisd/isis_pdu.c: don't accept more protocols than there's space for

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
1 file changed