Thread (3 messages) 3 messages, 2 authors, 3d ago

Re: [PATCH nf] netfilter: ip6tables: set hotdrop for malformed extension header matches

From: Zhixing Chen <hidden>
Date: 2026-07-13 03:10:26
Also in: netfilter-devel

Hi Phil,

Thanks a lot for the review.
There is another candidate for hotdrop in there, e.g. the "Packet
smaller than it's length field" check in line 76. Or is this a
legitimate non-match?
This should already be covered in the current nf/net tree by the previous
IPv6 extension header hotdrop fix, but I will double-check the base before
sending v2.
Given the many common blocks, maybe introduce a 'hotdrop' goto label to
jump to instead of break/return?
That makes sense to me for the repeated hbh error paths. I will look at
the flow again and use a hotdrop label where it keeps the code clearer.
I think the 'srh->segments_left > srh->first_segment' case is also a
candidate:
I will revisit this one and check it against RFC8200/RFC8754. My current
understanding is that this looks more like malformed input than a normal
rule mismatch, so I will account for it in v2 if the check fits cleanly.

Thanks,
Zhixing
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