[Cake] Re: [PATCH net 1/1] net/sched: sch_cake: validate 6in4 inner headers

["Toke Høiland-Jørgensen" <toke@toke.dk>]

> A malformed packet can therefore use an inner header with a non-IPv6
> version while still setting the byte used as nexthdr to TCP. When two
> packets from the same queued flow reach cake_ack_filter(), the version
> dispatch can fall through to WARN_ON(1), which becomes a denial of
> service on kernels with panic_on_warn enabled.

Hmm, I seem to recall a policy that says we don't care about
panic_on_warn-induced crashes? What say the maintainers?

That being said, I am not sure an unconditional WARN_ON really serves
any purpose here? As you've shown, this will most likely just be caused
by malformed packets.

So rather than add all these new checks, how about we just get rid of
the WARN_ON?

-Toke