Subject: Re: [PATCH net-next] bpf: add test for the verifier equal logic bug

From: Daniel Borkmann <[email-masked]>
Date: Tue, 29 Nov 2016 20:06:40 +0100

On 11/29/2016 06:35 PM, Josef Bacik wrote:
> This is a test to verify that
>
> bpf: fix states equal logic for varlen access
>
> actually fixed the problem.  The problem was if the register we added to our map
> register was UNKNOWN in both the false and true branches and the only thing that
> changed was the range then we'd incorrectly assume that the true branch was
> valid, which it really wasnt.  This tests this case and properly fails without
> my fix in place and passes with it in place.
>
> Signed-off-by: Josef Bacik <[email-masked]>

Acked-by: Daniel Borkmann <[email-masked]>

Thanks a lot for the test case! They are always useful to have ... which
just reminds me: it seems we didn't add anything for f23cc643f9ba ("bpf:
fix range arithmetic for bpf map access"). ;-)