在 2025/8/21 14:57, Florian Westphal 写道:

Wang Liang [off-list ref] wrote:

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在 2025/8/20 19:31, Florian Westphal 写道:

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Wang Liang [off-list ref] wrote:

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Previous commit 2d72afb34065 ("netfilter: nf_conntrack: fix crash due to
removal of uninitialised entry") move the IPS_CONFIRMED assignment after
the hash table insertion.

How is that related to this change?
As you write below, the bug came in with 62e7151ae3eb.

Before the commit 2d72afb34065, __nf_conntrack_confirm() set
'ct->status |= IPS_CONFIRMED;' before check hash, the warning will not
happen, so I put it here.

Oh, right, the problem was concealed before this.

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There is a second bug here, confirm can return NF_DROP and
nfct will be NULL.

Thanks for your suggestion!

Do you mean that ct may be deleted in confirm and return NF_DROP, so we can
not visit it in br_nf_local_in() and need to add 'case NF_DROP:' here?

I cannot find somewhere set skb->_nfct to NULL and return NF_DROP. Can you
give some hints?

You are right, skb->_nfct isn't set to NULL in case NF_DROP is returned.
However, the warning will trigger as we did not insert the conntrack
entry in that case.

I suggest to remove the warning, I don't think it buys anything.

Thanks.

Yes, remove the warning is a good a choice. I will remove the two lines in
v2 patch later, please check it.

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Best regards
Wang Liang