login: panic: _mtx_lock_sleep: recursed on non-recursive mutex rtentry @ /syzkaller/managers/main/kernel/sys/net/route.c:470

cpuid = 0
time = 1559575590
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0020e21fb0
vpanic() at vpanic+0x1e0/frame 0xfffffe0020e22010
panic() at panic+0x43/frame 0xfffffe0020e22070
__mtx_lock_sleep() at __mtx_lock_sleep+0x71a/frame 0xfffffe0020e22110
__mtx_lock_flags() at __mtx_lock_flags+0x157/frame 0xfffffe0020e22170
rtalloc1_fib() at rtalloc1_fib+0x16e/frame 0xfffffe0020e22280
ifa_ifwithroute() at ifa_ifwithroute+0x136/frame 0xfffffe0020e222c0
rt_getifa_fib() at rt_getifa_fib+0x255/frame 0xfffffe0020e22330
rtrequest1_fib() at rtrequest1_fib+0xe3f/frame 0xfffffe0020e22450
route_output() at route_output+0x1259/frame 0xfffffe0020e226d0
sosend_generic() at sosend_generic+0x73d/frame 0xfffffe0020e227a0
sosend() at sosend+0xc6/frame 0xfffffe0020e22810
kern_sendit() at kern_sendit+0x35e/frame 0xfffffe0020e228c0
sendit() at sendit+0x225/frame 0xfffffe0020e22920
sys_sendto() at sys_sendto+0x5c/frame 0xfffffe0020e22980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0020e22ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0020e22ab0
--- syscall (0, FreeBSD ELF64, nosys), rip = 0x41c38a, rsp = 0x7fffffffead8, rbp = 0x7fffffffeb40 ---
KDB: enter: panic
[ thread pid 759 tid 100081 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why