siftr LOR: PFil hook read/write mutex vs. tcp

1st 0xffffffff80990308 PFil read/write mutex (PFil hook read/write
mutex _at_ /usr/src/head/sys/net/pfil.c:77
2nd 0xffffffff80991528 tcp (tcp)
_at_ /usr/src/head/sys/modules/siftr/../../netinet/siftr.c:702
KDB: stack backtrace:
db_trace_self_wrapper()
kdb_backtrace()
_witness_debugger()
witness_checkorder()
_rw_rlock()
siftr_chkpkt()
pfil_run_hooks()
ip_input()
netisr_dispatch_src()
ether_demux()
ether_input()
msk_handle_events()
msk_intr()
intr_event_execute_handlers()
ithread_loop()
fork_exit()
fork_trampoline()
--- trap 0, rip = 0, rsp = 0xffffff8123559cf0, rbp = 0 ---

-- 
Bruce Cran