Re: [PATCH bpf v8 1/2] net: Validate protocol in skb_steal_sock() for BPF-assigned sockets

[Jiayuan Chen]

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.