panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 759
Starting stack trace...
panic(ffffffff827a7da4) at panic+0x16f sys/kern/subr_prf.c:229
__assert(ffffffff82827235,ffffffff82821ebd,2f7,ffffffff82773a94) at __assert+0x29 sys/kern/subr_prf.c:157
arptfree(fffffd80693adbe0) at arptfree+0x132 sys/netinet/if_ether.c:759
arptimer(ffffffff82c9b0a0) at arptimer+0x88 sys/netinet/if_ether.c:135
timeout_run(ffffffff82c9b0a0) at timeout_run+0xd0 sys/kern/kern_timeout.c:665
softclock_thread_mp(ffff800021158aa0) at softclock_thread_mp+0xc4 sys/kern/kern_timeout.c:833
end trace frame: 0x0, count: 251
End of stack trace.