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Code Block
bgColor#FFcccc
class ReadNames {
  private Vector<String> names = new Vector<String>();
  private final InputStreamReader input;
  private final BufferedReader reader;

  public ReadNames(String filename) throws IOException {
    this.input = new FileReader(filename);
    this.reader = new BufferedReader(input);
  }

  public void addNames() throws IOException {
    try {
      String newName;
      while (((newName = reader.readLine()) != null) &&
             !(newName.equalsIgnoreCase("quit"))) {
        names.addElement(newName);
        System.out.println("adding " + newName);
      }
    } finally {
      input.close();
    }
  }

  public static void main(String[] args) throws IOException {
    if (args.length != 1) {
      System.out.println("Arguments: [filename]");
      return;
    }
    ReadNames demo = new ReadNames(args[0]);
    demo.addNames();
  }
}

Wiki MarkupThe code places no upper bounds on the memory space required to execute the program. Consequently, the program can easily exhaust the available heap space in two ways. First, an attacker can supply arbitrarily many lines in the file, causing the vector to grow until memory is exhausted. Second, an attacker can simply supply an arbitrarily long line, causing the {{readLine()}} method to exhaust memory. According to the Java API documentation \ [[API 2006|AA. References#API 06]\], the {{BufferedReader.readLine()}} method

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

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Noncompliant Code Example

Wiki MarkupIn a server-class machine using a parallel garbage collector, the default initial and maximum heap sizes are as follows for Java SE 6 \[ [Sun 2006|AA. References#Sun 06]\]:

  • initial heap size: larger of 1/64 of the machine's physical memory or some reasonable minimum.
  • maximum heap size: smaller of 1/4 of the physical memory or 1GB.

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Code Block
bgColor#ccccff
  // ...
  int count = 10000000;
  // ...

Compliant Solution

Wiki MarkupThe {{OutOfMemoryError}} can be avoided by ensuring the absence of infinite loops, memory leaks, and unnecessary object retention. When memory requirements are known ahead of time, the heap size can be tailored to fit the requirements using the following runtime parameters \[ [Java 2006|AA. References#Java 06]\]:

java -Xms<initial heap size> -Xmx<maximum heap size>

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CERT C Secure Coding Standard

MEM11-C. Do not assume infinite heap space

CERT C++ Secure Coding Standard

MEM12-CPP. Do not assume infinite heap space

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="74bc461e-9583-4f93-9391-d681fa6f0ccd"><ac:plain-text-body><![CDATA[

[ISO/IEC TR 24772:2010

http://www.aitcnet.org/isai/]

Resource Exhaustion [XZP]

]]></ac:plain-text-body></ac:structured-macro>

MITRE CWE

CWE-400. Uncontrolled resource consumption ("resource exhaustion")

 

CWE-770. Allocation of resources without limits or throttling

Bibliography

ISO/IEC TR 24772:2010

Resource Exhaustion [XZP]

MITRE CWE

CWE-400. Uncontrolled resource consumption ("resource exhaustion")

 

CWE-770. Allocation of resources without limits or throttling

Bibliography

[API 2006]

Class ObjectInputStream and ObjectOutputStream

[Java 2006]

java – The Java application launcher, Syntax for increasing the heap size

[SDN 2008]

Serialization FAQ

[Sun 2003]

Chapter 5, Tuning the Java Runtime System, Tuning the Java Heap

[Sun 2006]

Garbage Collection Ergonomics

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="39dda6cc-426b-4371-b6c5-c23c98be45f3"><ac:plain-text-body><![CDATA[

[[API 2006

AA. References#API 06]]

Class ObjectInputStream and ObjectOutputStream

]]></ac:plain-text-body></ac:structured-macro>

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="1d50f10e-c603-47a4-bcb6-4f1640f755e7"><ac:plain-text-body><![CDATA[

[[Java 2006

AA. References#Java 06]]

[java – The Java application launcher

http://java.sun.com/javase/6/docs/technotes/tools/windows/java.html], Syntax for increasing the heap size

]]></ac:plain-text-body></ac:structured-macro>

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="19d31a1a-3955-494c-81bf-4cd88c6f313b"><ac:plain-text-body><![CDATA[

[[SDN 2008

AA. References#SDN 08]]

[Serialization FAQ

http://java.sun.com/javase/technologies/core/basic/serializationFAQ.jsp]

]]></ac:plain-text-body></ac:structured-macro>

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="223363ab-c35c-4bdc-a676-a5456e5125c4"><ac:plain-text-body><![CDATA[

[[Sun 2003

AA. References#Sun 03]]

Chapter 5, Tuning the Java Runtime System, [Tuning the Java Heap

http://docs.sun.com/source/817-2180-10/pt_chap5.html#wp57027]

]]></ac:plain-text-body></ac:structured-macro>

<ac:structured-macro ac:name="unmigrated-wiki-markup" ac:schema-version="1" ac:macro-id="e4407604-3785-42ae-b417-41baf2ecf9d5"><ac:plain-text-body><![CDATA[

[[Sun 2006

AA. References#Sun 06]]

[Garbage Collection Ergonomics

http://java.sun.com/javase/6/docs/technotes/guides/vm/gc-ergonomics.html ], Default values for the Initial and Maximum Heap Size ]]></ac:plain-text-body></ac:structured-macro>

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      49. Miscellaneous (MSC)