Fix double-free of cached WASM module in fizzy vm_manager - #7
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fizzy_vm_backend::run() caches a parsed module in a module_guard (frees it via fizzy_free_module), then passes the same pointer to fizzy_resolve_instantiate, which per fizzy's API takes ownership of the module and frees it via fizzy_free_instance. The same FizzyModule is freed twice. A double free is UB that a strict allocator crashes on (macOS 26 SDK: EXC_BAD_ACCESS in fizzy::Module::~Module during module_cache teardown) while older allocators tolerate it silently. Instantiate a fizzy_clone_module() copy so the FizzyInstance owns its own module and the cache keeps the original, and make module_guard non-copyable/non-movable. Verified in the koinos-chain twin (koinos/koinos-chain#862) with an AddressSanitizer build: zero ASan errors, full suite green. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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vm_manageras koinos-chain and carries the same double-free.fizzy_vm_backend::run()caches a parsed WASM module in amodule_guard(frees it viafizzy_free_module), then passes the same pointer tofizzy_resolve_instantiate, which per fizzy's API takes ownership of the module and frees it viafizzy_free_instance. The sameFizzyModuleis freed twice.A double free is UB that surfaces only under a strict allocator: it crashes deterministically on the macOS 26 SDK (
EXC_BAD_ACCESSinfizzy::Module::~Moduleduringmodule_cacheteardown) and is tolerated silently on older allocators.Fix: instantiate a
fizzy_clone_module()copy so the instance owns its own module and the cache keeps the original; makemodule_guardnon-copyable/non-movable.Twin of koinos/koinos-chain#862, where it was root-caused with AddressSanitizer (zero ASan errors after the fix, full suite green).