Re: KASAN: use-after-free Read in path_lookupat

[Linus Torvalds]

On Mon, Mar 25, 2019 at 3:04 PM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
>
> I'm fine either way, I think the rcu_destroy_inode would indeed simplify
> it nicely. In any case fwiw, here's what I'd have ready for standby on bpf
> side and tested as well. Decided to get rid of bpf_evict_inode() entirely
> since the only callback we'd really need is on final inode destruction:

Yes, this looks correct to me.

I think this is worth doing regardless. Even if we then make the vfs
layer add that rcu_destroy_inode(), that will fit very well with this
patch, and getting rid of the special bpf_evict_inode() logic and just
letting the normal vfs inode cleanup happen looks like the right
thing.

So ack from me on your

> Subject: [PATCH bpf] bpf: fix use after free in bpf_evict_inode

patch regardless of what else we might end up doing in this area to
clean things up.

                 Linus