Re: kasan for bpf

From: David Miller
Date: Sat Dec 23 2017 - 11:04:14 EST


From: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
Date: Fri, 22 Dec 2017 20:31:56 -0800

> Thoughts?

Even though you propose it as the opposite, it sounds like a crutch
for the verifier.

If we strictly control objects that the eBPF program can access,
verifier ensures this, and all other objects go through helpers,
then I cannot see what kasan for bpf can buy us.

To me it tells the world "yes, verifier and carefully designed helpers
are insufficient" and that's not the message I have been giving to
rooms full of hundreds of people listening to my xdp/bpf
presentations.