panic: udp_output: shared udbinfo lock, excl inp lock cpuid = 0 time = 1553421080 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe001fa22560 vpanic() at vpanic+0x1e0/frame 0xfffffe001fa225c0 panic() at panic+0x43/frame 0xfffffe001fa22620 udp_send() at udp_send+0x1377/frame 0xfffffe001fa22730 sosend_dgram() at sosend_dgram+0x550/frame 0xfffffe001fa227a0 sosend() at sosend+0xc6/frame 0xfffffe001fa22810 kern_sendit() at kern_sendit+0x35e/frame 0xfffffe001fa228c0 sendit() at sendit+0x226/frame 0xfffffe001fa22920 sys_sendmsg() at sys_sendmsg+0x8b/frame 0xfffffe001fa22980 amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe001fa22ab0 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe001fa22ab0 --- syscall (198, FreeBSD ELF64, nosys), rip = 0x412e7a, rsp = 0x7fffdfffdf38, rbp = 0x3 --- KDB: enter: panic [ thread pid 4278 tid 100986 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why