login: panic: mtx_lock() of spin mutex (null) @ /syzkaller/managers/main/kernel/sys/kern/uipc_sockbuf.c:360
cpuid = 0
time = 1571272035
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe001a162fe0
vpanic() at vpanic+0x1c7/frame 0xfffffe001a163050
panic() at panic+0x43/frame 0xfffffe001a1630b0
__mtx_lock_flags() at __mtx_lock_flags+0x203/frame 0xfffffe001a163110
socantrcvmore() at socantrcvmore+0x2c/frame 0xfffffe001a163130
sctp_notify_assoc_change() at sctp_notify_assoc_change+0x5b8/frame 0xfffffe001a1631a0
sctp_process_control() at sctp_process_control+0x8622/frame 0xfffffe001a163610
sctp_common_input_processing() at sctp_common_input_processing+0x751/frame 0xfffffe001a1637a0
sctp_input_with_port() at sctp_input_with_port+0x301/frame 0xfffffe001a163890
sctp_input() at sctp_input+0x1f/frame 0xfffffe001a1638b0
ip_input() at ip_input+0x2df/frame 0xfffffe001a163950
swi_net() at swi_net+0x21d/frame 0xfffffe001a1639f0
ithread_loop() at ithread_loop+0x2f2/frame 0xfffffe001a163a60
fork_exit() at fork_exit+0xac/frame 0xfffffe001a163ab0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe001a163ab0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 12 tid 100020 ]
Stopped at      kdb_enter+0x67: movq    $0,0x14776c6(%rip)