Invalidate borrowed packet views when the arena resets
A decoder stores a view into the arena across reset and later reads bytes belonging to a different packet.
- Focused work estimate
- 2h 30m + prerequisites
- Priority in the scenario
- Medium
- Engineering practice
- Lifetimes · Memory safety · Generations
Estimated field mix
- Systems programming70%
- Security30%
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Review it, then add it to your workspace.
The board opens an editable draft; nothing is saved until you confirm it. Sign-in and workspace permissions apply, and Demo boards remain ephemeral.
Project context
A fictional telemetry collector copies decoded packet fields into a small native arena. The prototype misaligns wide values and reuses memory while readers still hold views. Create a local Rust crate or C library with generated byte fixtures; no device traffic or production allocator replacement is supplied.
Setup prerequisites
- Pointers and slices
- Integer overflow
- Memory alignment
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
Acceptance criteria
- Views carry the generation in which they were created
- Reset advances generation before storage is reused
- Stale view access fails deterministically in the safe API
Implementation constraints
- Keep unsafe reads inside one reviewed boundary; do not claim runtime checks prove arbitrary raw pointers safe.
Verification to include
- Read several current-generation views before reset.
- Reset, reuse the same offset, and reject the older view.
Deliverables
- Generation-bound view API and stale-view reproduction
Rollout and recovery
Migrate the decoder through the checked view API before enabling reset reuse.
Value of the work
For the engineer: Practice representation invariants, lifetimes, unsafe-boundary review and memory diagnostics.
For the team: Review a component whose allocation failures and corruption cases are explicit before reuse in latency-sensitive code.
Evidence boundaries
Outcome Evidence: Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.
Ownership Evidence: Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence.