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

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Message-ID: <c2ea35d1-302c-671e-f976-9bb7ccf56197@fb.com>
Date:   Tue, 29 Nov 2016 14:50:15 -0500
From:   Josef Bacik <jbacik@...com>
To:     Daniel Borkmann <daniel@...earbox.net>, <davem@...emloft.net>,
        <netdev@...r.kernel.org>, <ast@...nel.org>, <jannh@...gle.com>,
        <kernel-team@...com>
Subject: Re: [PATCH net-next] bpf: add test for the verifier equal logic bug

On 11/29/2016 02:06 PM, Daniel Borkmann wrote:
> 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 <jbacik@...com>
>
> Acked-by: Daniel Borkmann <daniel@...earbox.net>
>
> 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"). ;-)

I was hoping you wouldn't notice ;).  I'll add one in the next couple of days. 
Thanks,

Josef