[TS] Empty environment variables as WASI's environ fetch leaks memory
authorMatt Corallo <git@bluematt.me>
Sun, 16 Jan 2022 23:33:07 +0000 (23:33 +0000)
committerMatt Corallo <git@bluematt.me>
Mon, 17 Jan 2022 04:34:51 +0000 (04:34 +0000)
typescript_strings.py

index 0d9f30b81b2293f09acb7b45f00745330e04f1a1..3596c2b8f34a988a745ac68f8ab5436e0706cd26 100644 (file)
@@ -73,21 +73,15 @@ imports.wasi_snapshot_preview1 = {
                // This is called before fd_write to format + print panic messages
                console.log("wasi_snapshot_preview1:environ_sizes_get");
                const out_count_view = new Uint32Array(wasm.memory.buffer, environ_var_count_ptr, 1);
-               out_count_view[0] = 1;
+               out_count_view[0] = 0;
                const out_len_view = new Uint32Array(wasm.memory.buffer, environ_len_ptr, 1);
-               out_len_view[0] = "RUST_BACKTRACE=1".length + 1; // Note that string must be NULL-terminated
+               out_len_view[0] = 0;
                return 0;
        },
        "environ_get": (environ_ptr: number, environ_buf_ptr: number) => {
                // This is called before fd_write to format + print panic messages
                console.log("wasi_snapshot_preview1:environ_get");
-               const out_ptrs = new Uint32Array(wasm.memory.buffer, environ_ptr, 2);
-               out_ptrs[0] = environ_buf_ptr;
-               out_ptrs[1] = "RUST_BACKTRACE=1".length;
-               const out_environ = new Uint8Array(wasm.memory.buffer, environ_buf_ptr, out_ptrs[1]);
-               for (var i = 0; i < out_ptrs[1]; i++) { out_environ[i] = "RUST_BACKTRACE=1".codePointAt(i); }
-               out_environ[out_ptrs[1]] = 0;
-               return 0;
+               return 58; // Note supported - we said there were 0 environment entries!
        },
        "proc_exit" : () => {
                console.log("wasi_snapshot_preview1:proc_exit");