panic: Assertion td->td_epochnest failed at /syzkaller/managers/i386/kernel/sys/kern/subr_epoch.c:398
cpuid = 0
time = 1570622494
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0022bdc190
vpanic() at vpanic+0x1e0/frame 0xfffffe0022bdc1f0
panic() at panic+0x43/frame 0xfffffe0022bdc250
_epoch_exit_preempt() at _epoch_exit_preempt+0x21c/frame 0xfffffe0022bdc2a0
ip6_output() at ip6_output+0x379c/frame 0xfffffe0022bdc550
udp6_send() at udp6_send+0xceb/frame 0xfffffe0022bdc720
sosend_dgram() at sosend_dgram+0x550/frame 0xfffffe0022bdc790
sosend() at sosend+0xc6/frame 0xfffffe0022bdc800
kern_sendit() at kern_sendit+0x33d/frame 0xfffffe0022bdc8b0
sendit() at sendit+0x227/frame 0xfffffe0022bdc910
sys_sendto() at sys_sendto+0x5c/frame 0xfffffe0022bdc970
ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe0022bdcab0
int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x814300f
KDB: enter: panic
[ thread pid 27647 tid 100287 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why