DecompressionStream should not accept data after the end #58247
Description
Version
24.0.1
Platform
Darwin macbook-air.taile5a6b.ts.net 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:34:14 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T8122 arm64
Subsystem
webstreams
What steps will reproduce the bug?
Run this in Node.js and browsers
deflate:
;(async () => {
const valid = new Uint8Array([120, 156, 75, 4, 0, 0, 98, 0, 98]) // deflate('a')
const empty = new Uint8Array(1)
const invalid = new Uint8Array([...valid, ...empty])
const double = new Uint8Array([...valid, ...valid])
for (const chunks of [[valid], [invalid], [valid, empty], [valid, valid], [double]]) {
try {
const stream = new Blob(chunks).stream().pipeThrough(new DecompressionStream('deflate'))
const useFrom = Array.fromAsync && stream.values
console.log(await (useFrom ? Array.fromAsync(stream) : new Response(stream).blob()))
} catch (e) {
console.error(e)
}
}
})()gzip:
;(async () => {
const valid = new Uint8Array([31, 139, 8, 0, 0, 0, 0, 0, 0, 19, 75, 4, 0, 67, 190, 183, 232, 1, 0, 0, 0]) // gzip('a')
const empty = new Uint8Array(1)
const invalid = new Uint8Array([...valid, ...empty])
const double = new Uint8Array([...valid, ...valid])
for (const chunks of [[valid], [invalid], [valid, empty], [valid, valid], [double]]) {
try {
const stream = new Blob(chunks).stream().pipeThrough(new DecompressionStream('gzip'))
const useFrom = Array.fromAsync && stream.values
console.log(await (useFrom ? Array.fromAsync(stream) : new Response(stream).blob()))
} catch (e) {
console.error(e)
}
}
})()How often does it reproduce? Is there a required condition?
Always
What is the expected behavior? Why is that the expected behavior?
First one should be valid and produce an blob/array with [97]
The other four with input past the end should throw a TypeError (see refs)
Chrome/Firefox/Safari are consistent with the spec and are throwing a TypeError on any input past the compressed stream.
- Chrome:
TypeError: Junk found after end of compressed data. - Firefox:
TypeError: Unexpected input after the end of stream - Safari:
TypeError: Extra bytes past the end.
What do you see instead?
All cases do not throw and produce [ 97 ] for deflate.
For gzip, concatenating inputs concatenates outputs, and [valid, valid] and [double] produce [97, 97] (all other produce [97]).
Additional information
Refs:
-
https://compression.spec.whatwg.org/#decompression-stream
If the end of the compressed input has not been reached, then throw a TypeError.
-
https://nodejs.org/api/webstreams.html#class-decompressionstream