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Subject: Re: [PATCH bpf v8 1/2] net: Validate protocol in skb_steal_sock() for
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To: Kuniyuki Iwashima <kuniyu@google.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
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On 6/10/26 1:14 AM, Kuniyuki Iwashima wrote:
>> Hi Kuniyuki and Alexei,
>>
>>
>> Thanks both for the discussion, it makes sense to me.
>>
>> I'll go back to fixing this in the helper itself, like the previous
>> version did.
> I think even the previous version is the same type of change
> for intentional misuse.
>
> Both bpf_sk_assign() and bpf_sk_assign_tcp_reqsk() assumes
> sk_lookup() in advance, meaning the bpf must have dissected
> skb, and bpf_sk_assign() relies on it and has no protocol check.


Hi Kuniyuki,

Fair point. The "immutable skb" idea is more more worthy.