panic: vm_object_vndeallocate: bad object reference count cpuid = 0 time = 1557783106 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00212ea6f0 vpanic() at vpanic+0x1e0/frame 0xfffffe00212ea750 panic() at panic+0x43/frame 0xfffffe00212ea7b0 vm_object_collapse() at vm_object_collapse/frame 0xfffffe00212ea810 vn_mmap() at vn_mmap+0x2e3/frame 0xfffffe00212ea890 kern_mmap() at kern_mmap+0x8a8/frame 0xfffffe00212ea950 sys_mmap() at sys_mmap+0x38/frame 0xfffffe00212ea980 amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe00212eaab0 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00212eaab0 --- syscall (198, FreeBSD ELF64, nosys), rip = 0x41309a, rsp = 0x7fffdfffdf38, rbp = 0x6 --- KDB: enter: panic [ thread pid 984 tid 100336 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why