ALLOC.FNP : Free Null Pointer

JavaScript is not currently enabled, but is required for full CodeSonar manual search and browse functionality.

If you are viewing this file in your hub's Web GUI, enable JavaScript in your browser: you will also need it for GUI functionality.

If you opened this file directly from disk, your browser may be directly suppressing JavaScript functionality: certain browsers perform this suppression on local files (but not files delivered by web servers) for security reasons.

If you access the manual through the hub's Web GUI, the functionality will not be suppressed because the hub is a web server.
Alternatively, your browser may allow you to explicitly disable the security setting that suppresses functionality. See the CodeSonar FAQ for more information.

CodeSonar^® 9.2p0

CONFIDENTIAL

CodeSecure Inc

C and C++

Binaries

ALLOC.FNP : Free Null Pointer

Summary

An attempt to free a null pointer.

Properties

Class Name

Free Null Pointer

Significance

redundancy

Mnemonic

ALLOC.FNP

Categories

MisraC2025	MisraC2025:D.4.1	Run-time failures shall be minimized
MisraC2023	MisraC2023:D.4.1	Run-time failures shall be minimized
Misra2012	Misra2012:D.4.1	Run-time failures shall be minimized
CWE	CWE:590	Free of Memory not on the Heap

Availability

Available for C and C++.

Enabling

Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file.

WARNING_FILTER += discard class="Free Null Pointer"

Triggering Functions

Free Null Pointer warnings can be triggered by any function treated as a deallocator by CodeSonar:

any library function that is recognized as a deallocator because CodeSonar ships with a library model that identifies it as such, and
any function for which you have added a library model identifying it as a deallocator.

Example

#include <stdlib.h>

void free_null_pointer(char *p, char *q){
    free((void*)0);   /* 'Free Null Pointer' warning issued here */
    free(malloc(10)); /* 'Free Null Pointer' warning issued here:
                       * malloc() may return NULL if system runs out of memory
                       */
}

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.

To report problems with this documentation, please visit https://support.codesecure.com/.