lb: fix panic in orphan backend cleanup when addr is zero-value#44853
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dylandreimerink merged 1 commit intocilium:mainfrom Mar 25, 2026
Merged
lb: fix panic in orphan backend cleanup when addr is zero-value#44853dylandreimerink merged 1 commit intocilium:mainfrom
dylandreimerink merged 1 commit intocilium:mainfrom
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When a BPF map write fails (E2BIG) during service reconciliation, updateReferences is never called, leaving backendReferences stale. If a backend is later released as an orphan and then re-added, updateBackendRevision creates a new backendStates entry but did not set the addr field — leaving it as a zero-value L3n4Addr. On the next reconciliation, orphanBackends returns this entry and the agent calls orphanState.addr.IsIPv6() on the zero-value address, which panics with a nil pointer dereference. Fix this by setting s.addr = addr in updateBackendRevision so that backendStates entries always have a valid address regardless of whether updateReferences runs. Fixes: cilium#44852 Signed-off-by: Vipul Singh <singhvipul@microsoft.com>
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dylandreimerink
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Mar 25, 2026
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@tklauser we should backport this to v1.18 as well ? |
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When a BPF map write fails (E2BIG) during service reconciliation, updateReferences is never called, leaving backendReferences stale. If a backend is later released as an orphan and then re-added, updateBackendRevision creates a new backendStates entry but did not set the addr field — leaving it as a zero-value L3n4Addr.
On the next reconciliation, orphanBackends returns this entry and the agent calls orphanState.addr.IsIPv6() on the zero-value address, which panics with a nil pointer dereference.
Fix this by setting s.addr = addr in updateBackendRevision so that backendStates entries always have a valid address regardless of whether updateReferences runs.
Fixes: #44852