login: panic: Assertion in_epoch(net_epoch_preempt) failed at /syzkaller/managers/main/kernel/sys/netinet/igmp.c:3304 cpuid = 1 time = 1570621872 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe001a1596d0 vpanic() at vpanic+0x1e0/frame 0xfffffe001a159730 panic() at panic+0x43/frame 0xfffffe001a159790 igmp_fasttimo() at igmp_fasttimo+0x12f4/frame 0xfffffe001a159890 pffasttimo() at pffasttimo+0x6a/frame 0xfffffe001a1598d0 softclock_call_cc() at softclock_call_cc+0x216/frame 0xfffffe001a1599b0 softclock() at softclock+0xa3/frame 0xfffffe001a1599f0 ithread_loop() at ithread_loop+0x2f2/frame 0xfffffe001a159a60 fork_exit() at fork_exit+0xb0/frame 0xfffffe001a159ab0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe001a159ab0 --- trap 0, rip = 0, rsp = 0, rbp = 0 --- KDB: enter: panic [ thread pid 12 tid 100018 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why