[39.0.0] Prevent using shared memories with Memory#12021
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alexcrichton merged 2 commits intobytecodealliance:release-39.0.0from Nov 11, 2025
Merged
[39.0.0] Prevent using shared memories with Memory#12021alexcrichton merged 2 commits intobytecodealliance:release-39.0.0from
Memory#12021alexcrichton merged 2 commits intobytecodealliance:release-39.0.0from
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This commit fixes a few issues where it was possible to represent a wasm shared linear memory with the `wasmtime::Memory` type. This is not sound because `wasmtime::Memory` provides safe Rust access to the bytes where that is not possible with wasm shared memories. Shared memories in Rust must be represented by `SharedMemory`, not `wasmtime::Memory`. Specifically this commit prevents two vectors of this happening: 1. `Memory::new` now requires that the memory type specified is non-shared. Instead `SharedMemory::new` must be used instead. 2. Core dumps now skip over shared memories when iterating over all memories in the store. Supporting shared memories is a more invasive change and will happen on Wasmtime's `main` branch.
tschneidereit
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Nov 11, 2025
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bytecodealliance:release-39.0.0
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This commit fixes a few issues where it was possible to represent a wasm shared linear memory with the
wasmtime::Memorytype. This is not sound becausewasmtime::Memoryprovides safe Rust access to the bytes where that is not possible with wasm shared memories. Shared memories in Rust must be represented bySharedMemory, notwasmtime::Memory.Specifically this commit prevents two vectors of this happening:
Memory::newnow requires that the memory type specified is non-shared. InsteadSharedMemory::newmust be used instead.Core dumps now skip over shared memories when iterating over all memories in the store. Supporting shared memories is a more invasive change and will happen on Wasmtime's
mainbranch.