fix(dnssec): add defensive nil checks#7997
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Add length checks for req.Ns before accessing req.Ns[0] in the Delegation and NameError/NoData code paths of Sign(). Currently response.Typify guarantees len(req.Ns) >= 1 for these response types. It requires SOA or NS records in the authority section to classify a response as such, so this cannot be triggered in practice. The guards are added as defense-in-depth in case Typify's classification logic changes in the future. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
yongtang
approved these changes
Apr 1, 2026
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1. Why is this pull request needed and what does it do?
Add length checks for
req.Nsbefore accessingreq.Ns[0]in the Delegation and NameError/NoData code paths ofSign().Currently
response.Typifyguaranteeslen(req.Ns) >= 1for these response types. It requires SOA or NS records in the authority section to classify a response as such, so this cannot be triggered in practice. The guards are added as defense-in-depth in case Typify's classification logic changes in the future.2. Which issues (if any) are related?
Fixes #7991
3. Which documentation changes (if any) need to be made?
None.
4. Does this introduce a backward incompatible change or deprecation?
No.