Autoloading module: intpm.ko Starting background file system checks in 60 seconds. Mon Mar 18 01:43 FreeBSD/amd64 (ci-freebsd-main-2.c.syzkaller.internal) (ttyu0) Warning: Permanently added '10.128.0.30' (ECDSA) to the list of known hosts. 2019/03/18 01:45:23 parsed 1 programs 2019/03/18 01:45:23 executed programs: 0 2019/03/18 01:45:28 executed programs: 45 2019/03/18 01:45:33 executed programs: 92 login: panic: vm_page_unhold: hold count < 0!!! cpuid = 1 time = 1552873535 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00212726d0 vpanic() at vpanic+0x1e0/frame 0xfffffe0021272730 panic() at panic+0x43/frame 0xfffffe0021272790 vm_page_unhold_pages() at vm_page_unhold_pages+0x1e3/frame 0xfffffe00212727e0 pipe_write() at pipe_write+0x16d8/frame 0xfffffe00212728b0 dofilewrite() at dofilewrite+0xfd/frame 0xfffffe0021272910 kern_writev() at kern_writev+0x66/frame 0xfffffe0021272950 sys_writev() at sys_writev+0x50/frame 0xfffffe0021272980 amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0021272ab0 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0021272ab0 --- syscall (198, FreeBSD ELF64, nosys), rip = 0x412e5a, rsp = 0x7fffdffdcf38, rbp = 0x3 --- KDB: enter: panic [ thread pid 904 tid 100338 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why