panic: Assertion in_epoch(net_epoch_preempt) failed at /syzkaller/managers/main/kernel/sys/netinet/in_mcast.c:1319 cpuid = 0 time = 1570626961 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00243c04c0 vpanic() at vpanic+0x1e0/frame 0xfffffe00243c0520 panic() at panic+0x43/frame 0xfffffe00243c0580 in_leavegroup_locked() at in_leavegroup_locked+0x215/frame 0xfffffe00243c05e0 inp_setmoptions() at inp_setmoptions+0x1290/frame 0xfffffe00243c07b0 ip_ctloutput() at ip_ctloutput+0x823/frame 0xfffffe00243c0810 rip_ctloutput() at rip_ctloutput+0x2c9/frame 0xfffffe00243c0850 sosetopt() at sosetopt+0x101/frame 0xfffffe00243c08d0 kern_setsockopt() at kern_setsockopt+0x14f/frame 0xfffffe00243c0950 sys_setsockopt() at sys_setsockopt+0x33/frame 0xfffffe00243c0980 amd64_syscall() at amd64_syscall+0x477/frame 0xfffffe00243c0ab0 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00243c0ab0 --- syscall (198, FreeBSD ELF64, nosys), rip = 0x4132aa, rsp = 0x7fffdfffdf38, rbp = 0x5 --- KDB: enter: panic [ thread pid 6848 tid 100362 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why