SonarSource Rules
  • Products

    In-IDE

    Code Quality and Security in your IDE with SonarQube Ide

    IDE extension that lets you fix coding issues before they exist!

    Discover SonarQube for IDE

    SaaS

    Code Quality and Security in the cloud with SonarQube Cloud

    Setup is effortless and analysis is automatic for most languages

    Discover SonarQube Cloud

    Self-Hosted

    Code Quality and Security Self-Hosted with SonarQube Server

    Fast, accurate analysis; enterprise scalability

    Discover SonarQube Server
  • SecretsSecrets
  • ABAPABAP
  • AnsibleAnsible
  • ApexApex
  • AzureResourceManagerAzureResourceManager
  • CC
  • C#C#
  • C++C++
  • CloudFormationCloudFormation
  • COBOLCOBOL
  • CSSCSS
  • DartDart
  • DockerDocker
  • FlexFlex
  • GitHub ActionsGitHub Actions
  • GoGo
  • HTMLHTML
  • JavaJava
  • JavaScriptJavaScript
  • JSONJSON
  • JCLJCL
  • KotlinKotlin
  • KubernetesKubernetes
  • Objective CObjective C
  • PHPPHP
  • PL/IPL/I
  • PL/SQLPL/SQL
  • PythonPython
  • RPGRPG
  • RubyRuby
  • RustRust
  • ScalaScala
  • SwiftSwift
  • TerraformTerraform
  • TextText
  • TypeScriptTypeScript
  • T-SQLT-SQL
  • VB.NETVB.NET
  • VB6VB6
  • XMLXML
  • YAMLYAML
C

C static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C code

  • All rules 315
  • Vulnerability13
  • Bug76
  • Security Hotspot19
  • Code Smell207

  • Quick Fix 19
Filtered: 35 rules found
symbolic-execution
    Impact
      Clean code attribute
        1. The address of an automatic object should not be assigned to another object that may persist after the first object has ceased to exist

           Bug
        2. Variables should be initialized before use

           Bug
        3. Variables should not be accessed outside of their scope

           Bug
        4. Account validity should be verified when authenticating users with PAM

           Vulnerability
        5. Changing directories improperly when using "chroot" is security-sensitive

           Security Hotspot
        6. POSIX functions should not be called with arguments that trigger buffer overflows

           Vulnerability
        7. Server hostnames should be verified during SSL/TLS connections

           Vulnerability
        8. "pthread_mutex_t" should be unlocked in the reverse order they were locked

           Bug
        9. Only valid arguments should be passed to UNIX/POSIX functions

           Code Smell
        10. "pthread_mutex_t" should be properly initialized and destroyed

           Bug
        11. "pthread_mutex_t" should not be locked when already locked, or unlocked when already unlocked

           Bug
        12. Only valid arguments should be passed to stream functions

           Code Smell
        13. Using publicly writable directories is security-sensitive

           Security Hotspot
        14. Using clear-text protocols is security-sensitive

           Security Hotspot
        15. Blocking functions should not be called inside critical sections

           Code Smell
        16. Return value of "setuid" family of functions should always be checked

           Code Smell
        17. Size of variable length arrays should be greater than zero

           Code Smell
        18. "mktemp" family of functions templates should have at least six trailing "X"s

           Code Smell
        19. Appropriate size arguments should be passed to "strncat" and "strlcpy"

           Code Smell
        20. Server certificates should be verified during SSL/TLS connections

           Vulnerability
        21. Weak SSL/TLS protocols should not be used

           Vulnerability
        22. Integral operations should not overflow

           Bug
        23. Parameter values should be appropriate

           Bug
        24. Stack allocated memory and non-owned memory should not be freed

           Bug
        25. Closed resources should not be accessed

           Bug
        26. Dynamically allocated memory should be released

           Bug
        27. Freed memory should not be used

           Bug
        28. Memory locations should not be released more than once

           Bug
        29. Memory access should be explicitly bounded to prevent buffer overflows

           Bug
        30. Zero should not be a possible denominator

           Bug
        31. XML parsers should not be vulnerable to XXE attacks

           Vulnerability
        32. "nonnull" parameters and return values of "returns_nonnull" functions should not be null

           Bug
        33. Null pointers should not be dereferenced

           Bug
        34. Resources should be closed

           Bug
        35. Unused assignments should be removed

           Code Smell

        Null pointers should not be dereferenced

        intentionality - logical
        reliability
        Bug
        • cwe
        • symbolic-execution
        • cert

        Dereferencing a null pointer results in undefined behavior.

        Why is this an issue?

        What is the potential impact?

        How can I fix it?

        More Info

        A pointer to null, also known as a null pointer, is created by initializing a pointer object to 0, NULL, or in the case of C++ nullptr. A null pointer does neither point to an object nor to valid memory, and as a consequence dereferencing or accessing the memory pointed by such a pointer is undefined behavior.

        int deref() {
          int* ptr = 0;
          return *ptr; // Noncompliant: deference of a null pointer
        }
        

        In addition to using the * operator, accessing a member of a structure (using →) or an element of an array (using []) also leads to dereference of the pointer, and causes undefined behavior if performed on a pointer to null.

        int subscript() {
          int* ptr = 0;
          return ptr[2]; // Noncompliant: subscript operator used on null pointer
        }
        
        struct Aggregate {
          int x;
          int y;
        };
        
        int memberAccess() {
          struct Aggregate* ptr = 0;
          return ptr->x; // Noncompliant: member access on a null pointer
        }
        

        Finally, invoking a function pointer that holds a null value, dereferences the pointer, and too results in undefined behavior.

        void call() {
          void (*func)(int) = NULL; // func is a pointer to a function
          func(10); // Noncompliant: the invocation of a null function pointer
        }
        
          Available In:
        • SonarQube CloudDetect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories
        • SonarQube ServerAnalyze code in your
          on-premise CI
          Developer Edition
          Available Since
          9.1

        © 2008-2025 SonarSource SA. All rights reserved.

        Privacy Policy | Cookie Policy | Terms of Use