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Date:   Fri, 15 Jul 2022 16:56:54 -0700
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Subject: Re: [PATCH bpf-next v6 02/23] bpf/verifier: allow kfunc to read user
 provided context
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To:     Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        Jiri Kosina <jikos@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
        Dave Marchevsky <davemarchevsky@fb.com>,
        Joe Stringer <joe@cilium.io>, Jonathan Corbet <corbet@lwn.net>
Cc:     Tero Kristo <tero.kristo@linux.intel.com>,
        linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org
References: <20220712145850.599666-1-benjamin.tissoires@redhat.com>
 <20220712145850.599666-3-benjamin.tissoires@redhat.com>
From:   Yonghong Song <yhs@fb.com>
In-Reply-To: <20220712145850.599666-3-benjamin.tissoires@redhat.com>
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On 7/12/22 7:58 AM, Benjamin Tissoires wrote:
> When a kfunc was trying to access data from context in a syscall eBPF
> program, the verifier was rejecting the call.
> This is because the syscall context is not known at compile time, and
> so we need to check this when actually accessing it.
> 
> Check for the valid memory access and allow such situation to happen.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Acked-by: Yonghong Song <yhs@fb.com>