Starting background file system checks in 60 seconds. Fri Sep 27 03:31:00 UTC 2019 FreeBSD/amd64 (ci-freebsd-i386-1.c.syzkaller.internal) (ttyu0) Warning: Permanently added '10.128.10.30' (ECDSA) to the list of known hosts. 2019/09/27 03:31:10 parsed 1 programs 2019/09/27 03:31:10 executed programs: 0 login: panic: mtx_lock() of spin mutex (null) @ /syzkaller/managers/i386/kernel/sys/kern/uipc_sockbuf.c:360 cpuid = 1 time = 1569555071 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0019eeffd0 vpanic() at vpanic+0x1e0/frame 0xfffffe0019ef0030 panic() at panic+0x43/frame 0xfffffe0019ef0090 __mtx_lock_flags() at __mtx_lock_flags+0x1fd/frame 0xfffffe0019ef00f0 socantrcvmore() at socantrcvmore+0x2c/frame 0xfffffe0019ef0110 sctp_notify_assoc_change() at sctp_notify_assoc_change+0x5c9/frame 0xfffffe0019ef0190 sctp_process_control() at sctp_process_control+0x86b1/frame 0xfffffe0019ef0610 sctp_common_input_processing() at sctp_common_input_processing+0x755/frame 0xfffffe0019ef07a0 sctp_input_with_port() at sctp_input_with_port+0x30e/frame 0xfffffe0019ef0890 sctp_input() at sctp_input+0x1f/frame 0xfffffe0019ef08b0 ip_input() at ip_input+0x2c4/frame 0xfffffe0019ef0970 swi_net() at swi_net+0x23b/frame 0xfffffe0019ef09f0 ithread_loop() at ithread_loop+0x2f2/frame 0xfffffe0019ef0a60 fork_exit() at fork_exit+0xb0/frame 0xfffffe0019ef0ab0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0019ef0ab0 --- trap 0, rip = 0, rsp = 0, rbp = 0 --- KDB: enter: panic [ thread pid 12 tid 100017 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why