🐛 Bug Report — issue in workerd zlib implementation

[alexander-azizi-martin]

zlib.inflateRawSync throws Uncaught RangeError: Memory limit exceeded when maxOutputLength is set to exactly the expected inflated size of a zip file. Incrementing it by 1 resolves the issue.

Setup

wrangler.jsonc:

"rules": [
  {
    "type": "Data",
    "globs": ["**/*.zip"],
    "fallthrough": true,
  },
],

The following fails in a Cloudflare Worker with the error above:

import AdmZip from 'adm-zip';
import compressedData from './compressed.zip';

const zip = new AdmZip(compressedData);
const zipEntry = zip.getEntries()[0].getData();

adm-zip passes the exact expected size as maxOutputLength to zlib.inflateRawSync. The issue originates here and paching it to use expectedLength + 1 fixes the issue:

https://github.com/cthackers/adm-zip/blob/1cd32f7e0ad3c540142a76609bb538a5cda2292f/methods/inflater.js#L5

This seems to be a bug with the workerd implementation of zlib.

[anonrig]

Opened #6294 to fix this issue. Thank you for the report.