panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 758
Starting stack trace...
panic(ffffffff8279f281) at panic+0x16f sys/kern/subr_prf.c:229
__assert(ffffffff82820fac,ffffffff828199c3,2f6,ffffffff8276cb3b) at __assert+0x29 sys/kern/subr_prf.c:157
arptfree(fffffd8060c89a98) at arptfree+0x132 sys/netinet/if_ether.c:758
arptimer(ffffffff82c54b60) at arptimer+0x88 sys/netinet/if_ether.c:135
timeout_run(ffffffff82c54b60) at timeout_run+0xd0 sys/kern/kern_timeout.c:640
softclock_thread(ffff800021169298) at softclock_thread+0x124 sys/kern/kern_timeout.c:763
end trace frame: 0x0, count: 251
End of stack trace.