netdev - Re: [PATCH net 2/3] bpf: fix pattern matches for direct packet access

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Message-ID: <186b7772-3f78-1b68-86c2-960a825fbc46@gmail.com>
Date:   Sat, 21 Oct 2017 09:39:49 -0700
From:   John Fastabend <john.fastabend@...il.com>
To:     Daniel Borkmann <daniel@...earbox.net>, davem@...emloft.net
Cc:     alexei.starovoitov@...il.com, john.r.fastabend@...il.com,
        netdev@...r.kernel.org
Subject: Re: [PATCH net 2/3] bpf: fix pattern matches for direct packet access

On 10/20/2017 05:34 PM, Daniel Borkmann wrote:
> Alexander had a test program with direct packet access, where
> the access test was in the form of data + X > data_end. In an
> unrelated change to the program LLVM decided to swap the branches
> and emitted code for the test in form of data + X <= data_end.
> We hadn't seen these being generated previously, thus verifier
> would reject the program. Therefore, fix up the verifier to
> detect all test cases, so we don't run into such issues in the
> future.
> 
> Fixes: b4e432f1000a ("bpf: enable BPF_J{LT, LE, SLT, SLE} opcodes in verifier")
> Reported-by: Alexander Alemayhu <alexander@...mayhu.com>
> Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
> Acked-by: Alexei Starovoitov <ast@...nel.org>
> ---

Acked-by: John Fastabend <john.fastabend@...il.com>