When pru_sockaddr is called from kern_getsockname(), the vnet is set. This is also true when pru_peeraddr is called via kern_getpeername(). However, the vnet is not net when these functions are called from soo_fill_kinfo(). This patch ensures that the vnet is also set in this case.

The corresponding SCTP functions assume the vnet to be set correctly. Right now, when a program with an wildcard bound SCTP socket crashes, the machines panics when trying to write the core file.