Should not be able to `path_open` absolute path

nodejs / uvwasi

WASI syscall API built atop libuv

MIT License

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Should not be able to `path_open` absolute path #269

Closed yagehu closed 1 month ago

yagehu commented 1 month ago

path_open an absolute path should error. This behavior is consistent amongst Wasmtime, WasmEdge, Wazero, WAMR. Fixing this does not break clients using wasi-libc as it already strips the prefix by matching the path with the appropriate preopened directory.

WASI folks have also stated absolute path should not work at the raw WASI level. https://github.com/WebAssembly/WASI/issues/374

cjihrig commented 1 month ago

@yagehu it would be fantastic if you could implement the openat() algorithm used by WASI for sandboxing. There is some discussion about it in https://github.com/libuv/libuv/issues/4167. You could implement it directly in uvwasi if you don't want to send a PR to libuv. If that were implemented, I believe we could revert https://github.com/nodejs/uvwasi/commit/1da5f325af83d80fae20da75cdcfa1b308c50ada