netty: Netty DNS Resolver cannot handle DNS Response with A, AAAA and NS records: SearchDomainUnknownHostException

Context

We are using Netty in our Java applications running on Azure Container Apps (which runs on top of Kubernetes internally). Our application regularly calls a dependency, always using the same request. Our DNS Servers sometimes return just an A record, which is correctly handled by Netty, but sometimes they return additional information:

Standard query response 0x27cc A <URL> CNAME <URL-2> A <IP> NS b.root-servers.net NS m.root-servers.net NS d.root-servers.net NS h.root-servers.net NS f.root-servers.net NS c.root-servers.net NS g.root-servers.net NS i.root-servers.net NS e.root-servers.net NS a.root-servers.net NS k.root-servers.net NS l.root-servers.net NS j.root-servers.net A <IP> AAAA <IP> AAAA <IP> A <IP> AAAA <IP> AAAA <IP> AAAA <IP> AAAA <IP> A <IP> AAAA <IP> A <IP> A <IP> AAAA <IP> A <IP> AAAA <IP> AAAA <IP> A <IP> A <IP> A <IP> A <IP> OPT

The additional section should be ignored and the answer section should be correctly parsed.

Actual behavior

The longer DNS response produces the following Netty error:

 io.netty.resolver.dns.DnsResolveContext$SearchDomainUnknownHostException: Failed to resolve 'xyz.xyz-xyz.location.azurecontainerapps.io' [A(1)] and search domain query for configured domains failed as well: [k8se-apps.svc.cluster.local, svc.cluster.local, cluster.local]
	at io.netty.resolver.dns.DnsResolveContext.finishResolve(DnsResolveContext.java:1088)
	at io.netty.resolver.dns.DnsResolveContext.tryToFinishResolve(DnsResolveContext.java:1035)
	at io.netty.resolver.dns.DnsResolveContext.query(DnsResolveContext.java:422)
	at io.netty.resolver.dns.DnsResolveContext.access$700(DnsResolveContext.java:66)
	at io.netty.resolver.dns.DnsResolveContext$2.operationComplete(DnsResolveContext.java:493)
	at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:583)
	at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:559)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492)
	at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636)
	at io.netty.util.concurrent.DefaultPromise.setFailure0(DefaultPromise.java:629)
	at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:118)
	at io.netty.resolver.dns.DnsQueryContext.tryFailure(DnsQueryContext.java:261)
	at io.netty.resolver.dns.DnsQueryContext$4.run(DnsQueryContext.java:208)
	at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
	at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:153)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:403)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: io.netty.resolver.dns.DnsNameResolverTimeoutException: [32843: /127.0.0.11:53] DefaultDnsQuestion(xyz.xyz-xyz.location.azurecontainerapps.io. IN A) query '32843' via UDP timed out after 5000 milliseconds (no stack trace available)

Expected behavior

The DNS resolution should work without error.

Steps to reproduce

Simulate the above DNS response packet and pass to Netty.

OS version

ubuntu 22.04