login: panic: mtx_lock() of spin mutex (null) @ /syzkaller/managers/main/kernel/sys/netinet/sctputil.c:4531
cpuid = 1
time = 1557062921
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0021263570
vpanic() at vpanic+0x1e0/frame 0xfffffe00212635d0
panic() at panic+0x43/frame 0xfffffe0021263630
__mtx_lock_flags() at __mtx_lock_flags+0x1fd/frame 0xfffffe0021263690
sctp_add_to_readq() at sctp_add_to_readq+0x620/frame 0xfffffe0021263710
sctp_ulp_notify() at sctp_ulp_notify+0xe75/frame 0xfffffe0021263780
sctp_setopt() at sctp_setopt+0x99d0/frame 0xfffffe0021263810
sctp_ctloutput() at sctp_ctloutput+0x214/frame 0xfffffe0021263850
sosetopt() at sosetopt+0x101/frame 0xfffffe00212638d0
kern_setsockopt() at kern_setsockopt+0x158/frame 0xfffffe0021263950
sys_setsockopt() at sys_setsockopt+0x33/frame 0xfffffe0021263980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0021263ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0021263ab0
--- syscall (0, FreeBSD ELF64, nosys), rip = 0x457c0a, rsp = 0x7fffdfffdf78, rbp = 0x6b6308 ---
KDB: enter: panic
[ thread pid 965 tid 100352 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why