Kingdom: Time and State

Distributed computation is about time and state. That is, in order for more than one component to communicate, state must be shared, and all that takes time.

Most programmers anthropomorphize their work. They think about one thread of control carrying out the entire program in the same way they would if they had to do the job themselves. Modern computers, however, switch between tasks very quickly, and in multi-core, multi-CPU, or distributed systems, two events may take place at exactly the same time. Defects rush to fill the gap between the programmer's model of how a program executes and what happens in reality. These defects are related to unexpected interactions between threads, processes, time, and information. These interactions happen through shared state: semaphores, variables, the file system, and, basically, anything that can store information.

Code Correctness: Erroneous Synchronization

C/C++

Abstract

If a thread fails to unlock a mutex after signaling other threads, the other threads will remain locked waiting on the mutex.

Explanation

After a thread signals other threads waiting on a mutex, it must unlock the mutex by calling pthread_mutex_unlock() before another thread can begin running. If the signaling thread fails to unlock the mutex, the pthread_cond_wait() call in the second thread will not return and the thread will not execute.

Example 1: The following code signals another thread waiting on a mutex by calling pthread_cond_signal(), but fails to unlock the mutex the other thread is waiting on.


   ...
   pthread_mutex_lock(&count_mutex);

   // Signal waiting thread
   pthread_cond_signal(&count_threshold_cv);
   ...

References

[1] Standards Mapping - Common Weakness Enumeration CWE ID 373

[2] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000336, CCI-000366, CCI-001094

[3] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 1.3

[4] Standards Mapping - NIST Special Publication 800-53 Revision 4 CM-4 Security Impact Analysis (P2), CM-6 Configuration Settings (P1), SC-5 Denial of Service Protection (P1)

[5] Standards Mapping - NIST Special Publication 800-53 Revision 5 CM-4 Impact Analyses, CM-6 Configuration Settings, SC-5 Denial of Service Protection

[6] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service

[7] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9

[8] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II

[9] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II

[10] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II

[11] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II

[12] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II

[13] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II

[14] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II

[15] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II

[16] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II

[17] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II

[18] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II

[19] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II

[20] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II

[21] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II

[22] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II

[23] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II

[24] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II

[25] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II

[26] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II

[27] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II

[28] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II, APSC-DV-002950 CAT II

[29] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)

[30] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service

desc.structural.cpp.code_correctness_erroneous_synchronization