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rust.unbounded_memory

Stability High

Detects data structures that can grow without bounds, leading to OOM.

Why It Matters

Unbounded memory:

Causes OOM — Process killed by OS
Cascading failures — Other services impacted
Hard to diagnose — Gradual memory growth

Example

// ❌ Before (unbounded Vec)
fn collect_items(stream: impl Stream<Item = Item>) -> Vec<Item> {
    let mut items = Vec::new();
    while let Some(item) = stream.next().await {
        items.push(item); // Grows forever!
    }
    items
}

// ✅ After (with capacity limit)
fn collect_items(stream: impl Stream<Item = Item>, max: usize) -> Vec<Item> {
    let mut items = Vec::with_capacity(max.min(1000));
    while let Some(item) = stream.next().await {
        if items.len() >= max {
            break; // Stop at limit
        }
        items.push(item);
    }
    items
}

What Unfault Detects

Vecs without capacity hints growing in loops
HashMaps accepting unbounded input
Channels without buffer limits

Auto-Fix

Unfault adds capacity limits and bounds checks.