panic: Assertion in_epoch(net_epoch_preempt) failed at /syzkaller/managers/i386/kernel/sys/netinet/in_mcast.c:1319
cpuid = 1
time = 1570624962
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00243844a0
vpanic() at vpanic+0x1e0/frame 0xfffffe0024384500
panic() at panic+0x43/frame 0xfffffe0024384560
in_leavegroup_locked() at in_leavegroup_locked+0x215/frame 0xfffffe00243845c0
inp_setmoptions() at inp_setmoptions+0x1290/frame 0xfffffe0024384790
ip_ctloutput() at ip_ctloutput+0x823/frame 0xfffffe00243847f0
udp_ctloutput() at udp_ctloutput+0x171/frame 0xfffffe0024384840
sosetopt() at sosetopt+0x101/frame 0xfffffe00243848c0
kern_setsockopt() at kern_setsockopt+0x14f/frame 0xfffffe0024384940
sys_setsockopt() at sys_setsockopt+0x33/frame 0xfffffe0024384970
ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe0024384ab0
int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x81431fb
KDB: enter: panic
[ thread pid 32671 tid 100352 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why