panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 758
Starting stack trace...
panic(ffffffff82786cf3) at panic+0x159 sys/kern/subr_prf.c:229
__assert(ffffffff828016ec,ffffffff8282206b,2f6,ffffffff82751dba) at __assert+0x29 sys/kern/subr_prf.c:157
arptfree(fffffd8071db0b90) at arptfree+0x131 sys/netinet/if_ether.c:758
arptimer(ffffffff82c694e8) at arptimer+0x88 sys/netinet/if_ether.c:135
timeout_run(ffffffff82c694e8) at timeout_run+0x8f sys/kern/kern_timeout.c:665
softclock_thread(ffff8000215e97f8) at softclock_thread+0xc4 sys/kern/kern_timeout.c:809
end trace frame: 0x0, count: 251
End of stack trace.