[wasm2js] Escape module names in generated JavaScript output#8377
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sumleo wants to merge 1 commit intoWebAssembly:mainfrom
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[wasm2js] Escape module names in generated JavaScript output#8377sumleo wants to merge 1 commit intoWebAssembly:mainfrom
sumleo wants to merge 1 commit intoWebAssembly:mainfrom
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WebAssembly module and base names are arbitrary UTF-8 strings per the spec, and may contain JavaScript string metacharacters such as quotes, backslashes, and newlines. The wasm2js code generator was inserting these names directly into JavaScript string literals without escaping, which could produce syntactically invalid or exploitable JavaScript output. Add an escapeJSString() helper that escapes backslashes, single and double quotes, newlines, carriage returns, and the Unicode line/paragraph separators (U+2028, U+2029). Apply it at all three injection points: 1. emitPreES6: ES6 import 'from' clause (single-quote context) 2. emitPostES6: object literal keys (double-quote context) for imported functions, memories, and tables 3. initActiveSegments: imports['module']['base'] subscript access (single-quote context) for both module and base names
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Summary
WebAssembly module and base names are arbitrary UTF-8 strings per the spec, and may contain JavaScript string metacharacters such as quotes, backslashes, and newlines. The wasm2js code generator was inserting these names directly into JavaScript string literals without escaping, which could produce syntactically invalid or exploitable JavaScript output.
This PR adds an
escapeJSString()helper that escapes backslashes, single/double quotes, newlines, carriage returns, and the Unicode line/paragraph separators (U+2028, U+2029), and applies it at all three affected output points insrc/wasm2js.h:emitPreES6— ES6import ... from '...'clause (single-quote string context). A module name containing'would break out of the string literal.emitPostES6— Object literal keys written as"..."for imported functions, memories, and tables. A module name containing"would break out.initActiveSegments—imports['module']['base']subscript expressions. Both module and base names are interpolated into single-quote strings without escaping.Test plan
python3 check.py --binaryen-bin ./build/bin wasm2js)import->moduleandimport->baseinwasm2js.h