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Null Pointer Checking

D3-NPC
D3-NPC (Null Pointer Checking)

Definition

Checking if a pointer is NULL.

Synonyms: Nil Pointer Checking.

How it Works

Programmatically checking if a pointer is NULL before use.

Considerations

  • Pointers should be checked prior to use after they have, or may have been modified.
  • Note that it may vary by circumstance whether the caller, or callee is responsible for checking if a pointer is NULL.
  • Note: This resource should not be considered a definitive or exhaustive coding guideline.

Artifact Relationships:

This defensive technique is related to specific artifacts. Click the artifact node for more information.
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References

All
Guideline
External Knowledge Base

The following references were used to develop the Null Pointer Checking knowledge-base article.

(Note: the consideration of references does not imply specific functionality exists in an offering.)

SEI CERT C Coding Standard

Reference Type: Guideline Organization: Software Engineering Institute
Source:
https://wiki.sei.cmu.edu/confluence/display/c/EXP34-C.+Do+not+dereference+null+pointers

CWE-476: NULL Pointer Dereference

Reference Type: External Knowledge Base Organization: MITRE
Source:
https://cwe.mitre.org/data/definitions/476.html

SEI CERT C Coding Standard

Reference Type: Guideline Organization: Software Engineering Institute
Source:
https://wiki.sei.cmu.edu/confluence/display/c/MEM10-C.+Define+and+use+a+pointer+validation+function

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