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CompositeByteBuf.addComponent doesn't guard agaist overflow

See original GitHub issue

Expected behavior

CompositeByteBuf.addComponent should throw an exception when adding a component overflows the maximum size of the buffer (Integer.MAX_VALUE).

Actual behavior

Both writableBytes and/or readableBytes (depending on setting for increaseWriterIndex) as well as capacity overflow into negative numbers.

Steps to reproduce

Run the reproducer in scala. Use a higher setting, e.g. -Xmx8G to experience the issue before running out of heap. Output will be something like:

400000000 400000000
800000000 800000000
1200000000 1200000000
1600000000 1600000000
2000000000 2000000000
-1894967296 -1894967296
-1494967296 -1494967296
-1094967296 -1094967296
-694967296 -694967296
-294967296 -294967296
105032704 105032704
...

Minimal yet complete reproducer code (or URL to code)

import io.netty.buffer.{ ByteBufAllocator, Unpooled }

object BufTest {
  def main(args: Array[String]): Unit = {
    val alloc = ByteBufAllocator.DEFAULT

    val buf = alloc.compositeBuffer()
    // We'll keep adding 400MB components
    while (true) {
      val arr = new Array[Byte](400 * 1000 * 1000)
      buf.addComponent(Unpooled.wrappedBuffer(arr))
      println(s"${buf.writableBytes()} ${buf.capacity()}")
    }
  }
}

Netty version

4.1.44 final

JVM version (e.g. `java -version`)

openjdk version "11.0.5" 2019-10-15 LTS
OpenJDK Runtime Environment Zulu11.35+15-CA (build 11.0.5+10-LTS)
OpenJDK 64-Bit Server VM Zulu11.35+15-CA (build 11.0.5+10-LTS, mixed mode)

OS version (e.g. `uname -a`)

Darwin Attilas-MacBook-Pro-4.local 18.7.0 Darwin Kernel Version 18.7.0: Mon Feb 10 21:08:45 PST 2020; root:xnu-4903.278.28~1/RELEASE_X86_64 x86_64

Issue Analytics

State:
Created 3 years ago
Comments:6 (3 by maintainers)

Top GitHub Comments

3reactions

szegedicommented, Apr 23, 2020

In one word: heavily 😄. All of network communication is async I/O based on Netty socket channel handler pipelines. We use the ByteBuf API pervasively too even outside of immediate domain of networking (disk I/O, internal transformations). It’s a nice (consistent, comprehensive, easy to understand) API to manipulate byte-based data, and if we’re smart about it then we also minimize copying when it’s time to send the bytes over the network.

0reactions

normanmaurercommented, Apr 23, 2020

@szegedi no problem … happy to help. Would love to hear more about how faunadb uses netty 😃