From 2a8ef7a1aff5428875a0092d81eb50259020f5a8 Mon Sep 17 00:00:00 2001
From: Alexey Orlenko <eaglexrlnk@gmail.com>
Date: Mon, 22 May 2017 21:45:57 +0300
Subject: [PATCH] zlib: fix node crashing on invalid options

This is a partial backport of semver-patch bits of
9e4660b5187d4be6a1484e705dc735c0e76ffafa.

This commit fixes the Node process crashing when constructors of classes
of the zlib module are given invalid options.

* Throw an Error when the zlib library rejects the value of windowBits,
  instead of crashing with an assertion.

* Treat windowBits and memLevel options consistently with other ones and
  don't crash when non-numeric values are given.

Backport-PR-URL: https://github.com/nodejs/node/pull/14860
PR-URL: https://github.com/nodejs/node/pull/13098
Fixes: https://github.com/nodejs/node/issues/13082
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
---
 doc/api/zlib.md                        |  4 ++++
 lib/zlib.js                            | 14 ++++++++++++--
 src/node_zlib.cc                       | 13 ++++++++-----
 test/parallel/test-zlib-failed-init.js | 13 +++++++++++++
 4 files changed, 37 insertions(+), 7 deletions(-)
 create mode 100644 test/parallel/test-zlib-failed-init.js

diff --git a/doc/api/zlib.md b/doc/api/zlib.md
index 8e5f14621b9dd1..6947b2047eae02 100644
--- a/doc/api/zlib.md
+++ b/doc/api/zlib.md
@@ -373,6 +373,10 @@ added: v0.5.8
 
 Returns a new [DeflateRaw][] object with an [options][].
 
+*Note*: The zlib library rejects requests for 256-byte windows (i.e.,
+`{ windowBits: 8 }` in `options`). An `Error` will be thrown when creating a
+[DeflateRaw][] object with this specific value of the `windowBits` option.
+
 ## zlib.createGunzip([options])
 <!-- YAML
 added: v0.5.8
diff --git a/lib/zlib.js b/lib/zlib.js
index ecddfda653f7cb..b94b06565be588 100644
--- a/lib/zlib.js
+++ b/lib/zlib.js
@@ -372,9 +372,19 @@ function Zlib(opts, mode) {
   var strategy = exports.Z_DEFAULT_STRATEGY;
   if (typeof opts.strategy === 'number') strategy = opts.strategy;
 
-  this._handle.init(opts.windowBits || exports.Z_DEFAULT_WINDOWBITS,
+  var windowBits = exports.Z_DEFAULT_WINDOWBITS;
+  if (opts.windowBits && typeof opts.windowBits === 'number') {
+    windowBits = opts.windowBits;
+  }
+
+  var memLevel = exports.Z_DEFAULT_MEMLEVEL;
+  if (opts.memLevel && typeof opts.memLevel === 'number') {
+    memLevel = opts.memLevel;
+  }
+
+  this._handle.init(windowBits,
                     level,
-                    opts.memLevel || exports.Z_DEFAULT_MEMLEVEL,
+                    memLevel,
                     strategy,
                     opts.dictionary);
 
diff --git a/src/node_zlib.cc b/src/node_zlib.cc
index 304fbf72fed44f..66a6a476a7c7b2 100644
--- a/src/node_zlib.cc
+++ b/src/node_zlib.cc
@@ -469,16 +469,19 @@ class ZCtx : public AsyncWrap {
         CHECK(0 && "wtf?");
     }
 
-    if (ctx->err_ != Z_OK) {
-      ZCtx::Error(ctx, "Init error");
-    }
-
-
     ctx->dictionary_ = reinterpret_cast<Bytef *>(dictionary);
     ctx->dictionary_len_ = dictionary_len;
 
     ctx->write_in_progress_ = false;
     ctx->init_done_ = true;
+
+    if (ctx->err_ != Z_OK) {
+      if (dictionary != nullptr) {
+        delete[] dictionary;
+        ctx->dictionary_ = nullptr;
+      }
+      ctx->env()->ThrowError("Init error");
+    }
   }
 
   static void SetDictionary(ZCtx* ctx) {
diff --git a/test/parallel/test-zlib-failed-init.js b/test/parallel/test-zlib-failed-init.js
new file mode 100644
index 00000000000000..afc2c82ddfca8e
--- /dev/null
+++ b/test/parallel/test-zlib-failed-init.js
@@ -0,0 +1,13 @@
+'use strict';
+
+require('../common');
+
+const assert = require('assert');
+const zlib = require('zlib');
+
+// For raw deflate encoding, requests for 256-byte windows are rejected as
+// invalid by zlib.
+// (http://zlib.net/manual.html#Advanced)
+assert.throws(() => {
+  zlib.createDeflateRaw({ windowBits: 8 });
+}, /^Error: Init error$/);