panic: Assertion in_epoch(net_epoch_preempt) failed at /syzkaller/managers/i386/kernel/sys/netinet/in_mcast.c:1319 cpuid = 1 time = 1570637512 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00243684b0 vpanic() at vpanic+0x1e0/frame 0xfffffe0024368510 panic() at panic+0x43/frame 0xfffffe0024368570 in_leavegroup_locked() at in_leavegroup_locked+0x215/frame 0xfffffe00243685d0 inp_setmoptions() at inp_setmoptions+0x1290/frame 0xfffffe00243687a0 ip_ctloutput() at ip_ctloutput+0x823/frame 0xfffffe0024368800 rip_ctloutput() at rip_ctloutput+0x2c9/frame 0xfffffe0024368840 sosetopt() at sosetopt+0x101/frame 0xfffffe00243688c0 kern_setsockopt() at kern_setsockopt+0x14f/frame 0xfffffe0024368940 sys_setsockopt() at sys_setsockopt+0x33/frame 0xfffffe0024368970 ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe0024368ab0 int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x81431ca KDB: enter: panic [ thread pid 1200 tid 100788 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why