panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 758
Starting stack trace...
panic(ffffffff8279f1c4) at panic+0x16f sys/kern/subr_prf.c:229
__assert(ffffffff8281f847,ffffffff828198cd,2f6,ffffffff8276cf55) at __assert+0x29 sys/kern/subr_prf.c:157
arptfree(fffffd8066e911d8) at arptfree+0x132 sys/netinet/if_ether.c:758
arptimer(ffffffff82ca3850) at arptimer+0x88 sys/netinet/if_ether.c:135
timeout_run(ffffffff82ca3850) at timeout_run+0xd0 sys/kern/kern_timeout.c:640
softclock_thread(ffff8000211682a8) at softclock_thread+0x124 sys/kern/kern_timeout.c:763
end trace frame: 0x0, count: 251
End of stack trace.