fix(kernel): wrap watch_queue monotonic id counters to avoid overflow#126
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create_queue/create_queue_with_capacity/create_group incremented next_queue_id/next_group_id with a plain '+= 1'. The occupancy guards cap only the concurrently-live count (MAX_QUEUES=256 / MAX_GROUPS=64), not the monotonic counter, so over a long-running create/destroy cycle the u32 id reaches u32::MAX and the next increment panics under overflow-checks. Use wrapping_add, matching the next_*_id idiom already used in sysfs_attr.rs and perf_events.rs: the bounded live count makes id reuse after a 2^32 wrap a non-issue in practice. Latent: WatchQueueSubsystem is an exported pub module with no instance, syscall, or dispatch path today.
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Summary
create_queue/create_queue_with_capacity/create_groupincrementednext_queue_id/next_group_idwith a plain+= 1. The occupancy guards bound only the concurrently-live count (MAX_QUEUES=256/MAX_GROUPS=64), not the monotonic counter, so over a long-running create/destroy cycle the u32 id reachesu32::MAXand the next increment panics under overflow-checks.Use
wrapping_add, matching thenext_*_ididiom already insysfs_attr.rs/perf_events.rs— the bounded live count makes id reuse after a 2^32 wrap a non-issue.Latent:
WatchQueueSubsystemis an exported pub module with no instance/syscall/dispatch path today. Found by a kernel security-parser fan-out (ptrace/landlock/perf/BTF/io_uring/seccomp/keyring all came back clean).Verification
cargo clippy -p oncrix-kernel -- -D warnings✓ (0) +cargo build -p oncrix-kernel --target x86_64-unknown-none✓ (bare-metal) +cargo fmt --all -- --check✓