Fatal trap 12: page fault while in kernel mode cpuid = 1; apic id = 01 fault virtual address = 0x30 fault code = supervisor read data , page not present instruction pointer = 0x20:0xffffffff8156d3aa stack pointer = 0x28:0xfffffe002121d7a0 frame pointer = 0x28:0xfffffe002121d7e0 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 3109 (syz-executor.0) trap number = 12 panic: page fault cpuid = 1 time = 1552943071 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe002121d400 vpanic() at vpanic+0x1e0/frame 0xfffffe002121d460 panic() at panic+0x43/frame 0xfffffe002121d4c0 trap_fatal() at trap_fatal+0x4c6/frame 0xfffffe002121d540 trap_pfault() at trap_pfault+0x9f/frame 0xfffffe002121d5b0 trap() at trap+0x44d/frame 0xfffffe002121d6d0 calltrap() at calltrap+0x8/frame 0xfffffe002121d6d0 --- trap 0xc, rip = 0xffffffff8156d3aa, rsp = 0xfffffe002121d7a0, rbp = 0xfffffe002121d7e0 --- vm_page_unhold_pages() at vm_page_unhold_pages+0x5a/frame 0xfffffe002121d7e0 pipe_write() at pipe_write+0x16d8/frame 0xfffffe002121d8b0 dofilewrite() at dofilewrite+0xfd/frame 0xfffffe002121d910 kern_writev() at kern_writev+0x66/frame 0xfffffe002121d950 sys_writev() at sys_writev+0x50/frame 0xfffffe002121d980 amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe002121dab0 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe002121dab0 --- syscall (198, FreeBSD ELF64, nosys), rip = 0x412e5a, rsp = 0x7fffdfffdf38, rbp = 0x3 --- KDB: enter: panic [ thread pid 3109 tid 100568 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why