June 2026 monthly summary for google/gvisor: Focused on hardening NAT evaluation stability in the inet NAT path to improve runtime reliability and reduce crash risk in mixed IPv4/IPv6 traffic. Implemented a fix that skips NAT rules whose NFTA_NAT_FAMILY does not match the packet's family, mirroring Linux nft_nat_eval behavior. The change prevents index-out-of-range panics during NAT evaluation and aligns with existing code paths (initNATOp, setupNetmap) to ensure safe iteration across address slices. Result: more stable networking for container workloads in gVisor with IPv4/IPv6 mixed traffic, lower incident risk, and a clearer path for future enhancements around NAT rule evaluation.

In May 2026, I focused on stabilizing patch processing in the Bazel repository (fmeum/bazel) by hardening PatchUtil against malformed inputs. I implemented length checks to prevent runtime StringIndexOutOfBoundsException when processing truncated mode lines, and routed failures through PatchFailedException with clear diagnostics. This change aligns with Bazel PR #29624, reducing crash risk and improving CI/build reliability without changing public APIs. The effort improves patch application reliability across environments and lowers maintenance costs by catching and reporting malformed patches earlier in the workflow.