Observed when running java/net/httpclient/http3/H3MultipleConnectionsToSameHost.java:

#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/da1065b5-7b94-4f0d-85e9-a3a252b9a32e-S17659/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/ba75c2ef-ef6c-496a-9dd9-0cfdd2448aac/runs/274c5de0-ff90-415c-8316-4f787781d2fc/workspace/open/src/hotspot/share/runtime/continuationFreezeThaw.cpp:1905), pid=3411511, tid=3411984
# Error: assert(!current->cont_fastpath() || freeze.check_valid_fast_path()) failed
#
# JRE version: Java(TM) SE Runtime Environment (26.0) (fastdebug build 26-internal-2025-11-26-1155018.daniel.jelinski.jdk)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 26-internal-2025-11-26-1155018.daniel.jelinski.jdk, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xc2f132] freeze_result freeze_internal<Config<(oop_kind)0, G1BarrierSet>, false>(JavaThread*, long*)+0x922


Current thread (0x00007fe844012c30): JavaThread "ForkJoinPool-1-worker-11" daemon [_thread_in_Java, id=3411984, stack(0x00007fe85abed000,0x00007fe85aced000) (1024K)]

Stack: [0x00007fe85abed000,0x00007fe85aced000], sp=0x00007fe85aceb000, free space=1016k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xc2f132] freeze_result freeze_internal<Config<(oop_kind)0, G1BarrierSet>, false>(JavaThread*, long*)+0x922 (continuationFreezeThaw.cpp:1905)
V [libjvm.so+0xc2f2f8] int freeze<Config<(oop_kind)0, G1BarrierSet> >(JavaThread*, long*)+0x58 (continuationFreezeThaw.cpp:272)
J 179 jdk.internal.vm.Continuation.doYield()I java.base@26-internal (0 bytes) @ 0x00007fe8cbe28e55 [0x00007fe8cbe28e00+0x0000000000000055]
J 7243 c2 jdk.internal.vm.Continuation.yield0(Ljdk/internal/vm/ContinuationScope;Ljdk/internal/vm/Continuation;)Z java.base@26-internal (354 bytes) @ 0x00007fe8cc190770 [0x00007fe8cc190700+0x0000000000000070]
J 7228 c2 sun.nio.ch.DatagramChannelImpl.receive(Ljava/nio/ByteBuffer;)Ljava/net/SocketAddress; java.base@26-internal (188 bytes) @ 0x00007fe8cc18295c [0x00007fe8cc181480+0x00000000000014dc]
J 7578% c2 jdk.internal.net.http.quic.QuicEndpoint.channelReadLoop()V java.net.http@26-internal (1046 bytes) @ 0x00007fe8cbed28d0 [0x00007fe8cbed2400+0x00000000000004d0]
j jdk.internal.net.http.quic.QuicEndpoint$QuicVirtualThreadedEndpoint.channelReadLoop0()V+1 java.net.http@26-internal
j jdk.internal.net.http.quic.QuicEndpoint$QuicVirtualThreadedEndpoint$$Lambda+0x000000004810ee20.run()V+4 java.net.http@26-internal