ALLOC.DF : Double Free

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CodeSonar^® 9.2p0

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CodeSecure Inc

C and C++

Binaries

ALLOC.DF : Double Free

Summary

Two attempts to free the same dynamic object.

Properties

Class Name

Double Free

Significance

security

Mnemonic

ALLOC.DF

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
MisraC++2023	MisraC++2023:0.3.2	A function call shall not violate the function's preconditions
	MisraC++2023:15.8.1	User-provided copy assignment and move assignment operators shall handle self-assignment
CWE	CWE:415	Double Free
	CWE:763	Release of Invalid Pointer or Reference
TS17961	TS17961:5.22-dblfree	Freeing memory multiple times
CERT-C	CERT-C:MEM00-C	Allocate and free memory in the same module, at the same level of abstraction
	CERT-C:MEM01-C	Store a new value in pointers immediately after free()
CERT-CPP	CERT-CPP:MEM51-CPP	Properly deallocate dynamically allocated resources
	CERT-CPP:OOP54-CPP	Gracefully handle self-copy assignment
JSF++	JSF++:81	The assignment operator shall handle self-assignment correctly.

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="Double Free"

Triggering Functions

Double Free 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 double_free(void){
    char *p = malloc(10);
    if (!p){
      return;
    }
    char *q = p;                                /* aliasing is taken into account */
    free(p);
    free(q);  /* 'Double Free' warning issued here */
}

Relevant Configuration File Parameters

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

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