CVE-2026-34988 Wasmtime线性内存泄露漏洞

// Vulnerable Configuration Example for CVE-2026-34988 // This demonstrates the settings required to trigger the memory leak. use wasmtime::*; fn main() -> Result<()> { // Configure the engine with pooling allocator let mut config = Config::new(); config.wasm_pooling_allocation(true); // Set vulnerable conditions: // 1. memory_guard_size must be 0 config.memory_guard_size(0); // 2. memory_reservation must be < 4GiB (e.g., 2GiB) let reservation_size = 2 * 1024 * 1024 * 1024; config.memory_reservation(reservation_size); // Note: The allocator must be configured such that max_memory_size // matches the memory_reservation value to trigger the bug. let engine = Engine::new(&config)?; // A dummy module let module = Module::new(&engine, "(module (memory 1))")?; let mut store = Store::new(&engine, ()); let instance = Instance::new(&mut store, &module, &[])?; // Instance 1 writes sensitive data let memory = instance.get_memory(&mut store, "memory").unwrap(); memory.write(&mut store, 0, b"SECRET_DATA")?; // Drop instance 1, memory is returned to pool drop(instance); // Instance 2 reuses memory let instance2 = Instance::new(&mut store, &module, &[])?; // If instance 2 performs an out-of-bounds read due to incorrect // permissions not being reset, it might read "SECRET_DATA" Ok(()) }