Re: [PATCH bpf-next 2/2] selftests/bpf: Cover small conntrack opts error writes

[bot+bpf-ci@kernel.org]

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> selftests/bpf: Cover small conntrack opts error writes
>
> Add a conntrack kfunc regression check for opts__sz values that do not
> cover opts->error. The BPF program initializes opts->error with a guard
> value, calls the lookup and allocation kfuncs with opts__sz set to
> sizeof(opts->netns_id), and verifies that the guard is still intact
> after the kfunc returns NULL.
>
> Without the conntrack wrapper guard, the kfunc error path overwrites
> that guard with -EINVAL even though the verifier checked only the first
> four bytes of the options object.
>
> Signed-off-by: Yiyang Chen <chenyy23@mails.tsinghua.edu.cn>

This is a regression test for the out-of-bounds opts->error write that
is fixed in the prior series commit 86b813c37ee5 ("bpf: Guard conntrack
opts error writes"), but it carries no Fixes: tags.

A regression test usually carries the same Fixes: tags as the fix it
covers, so it gets backported to stable alongside that fix. The two new
test cases map onto the two commits that introduced the kfuncs: the
small-opts lookup case covers the lookup kfunc and the small-opts alloc
case covers the alloc kfunc.

Should this include:

  Fixes: b4c2b9593a1c ("net/netfilter: Add unstable CT lookup helpers for XDP and TC-BPF")
  Fixes: d7e79c97c00c ("net: netfilter: Add kfuncs to allocate and insert CT")


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