cwetest/CWE476_NULL_Pointer_Dereference__binary_if_04.c

/* TEMPLATE GENERATED TESTCASE FILE
Filename: CWE476_NULL_Pointer_Dereference__binary_if_04.c
Label Definition File: CWE476_NULL_Pointer_Dereference.pointflaw.label.xml
Template File: point-flaw-04.tmpl.c
*/
/*
 * @description
 * CWE: 476 NULL Pointer Dereference
 * Sinks: binary_if
 *    GoodSink: Do not check for NULL after the pointer has been dereferenced
 *    BadSink : Check for NULL after a pointer has already been dereferenced
 * Flow Variant: 04 Control flow: if(STATIC_CONST_TRUE) and if(STATIC_CONST_FALSE)
 *
 * */

#include "std_testcase.h"

/* The two variables below are declared "const", so a tool should
   be able to identify that reads of these will always return their
   initialized values. */
static const int STATIC_CONST_TRUE = 1; /* true */
static const int STATIC_CONST_FALSE = 0; /* false */

#ifndef OMITBAD

void CWE476_NULL_Pointer_Dereference__binary_if_04_bad()
{
    if(STATIC_CONST_TRUE)
    {
        {
            twoIntsStruct *twoIntsStructPointer = NULL;
            /* FLAW: Using a single & in the if statement will cause both sides of the expression to be evaluated
             * thus causing a NPD */
            if ((twoIntsStructPointer != NULL) & (twoIntsStructPointer->intOne == 5))
            {
                printLine("intOne == 5");
            }
        }
    }
}

#endif /* OMITBAD */

#ifndef OMITGOOD

/* good1() uses if(STATIC_CONST_FALSE) instead of if(STATIC_CONST_TRUE) */
static void good1()
{
    if(STATIC_CONST_FALSE)
    {
        /* INCIDENTAL: CWE 561 Dead Code, the code below will never run */
        printLine("Benign, fixed string");
    }
    else
    {
        {
            twoIntsStruct *twoIntsStructPointer = NULL;
            /* FIX: Use && in the if statement so that if the left side of the expression fails then
             * the right side will not be evaluated */
            if ((twoIntsStructPointer != NULL) && (twoIntsStructPointer->intOne == 5))
            {
                printLine("intOne == 5");
            }
        }
    }
}

/* good2() reverses the bodies in the if statement */
static void good2()
{
    if(STATIC_CONST_TRUE)
    {
        {
            twoIntsStruct *twoIntsStructPointer = NULL;
            /* FIX: Use && in the if statement so that if the left side of the expression fails then
             * the right side will not be evaluated */
            if ((twoIntsStructPointer != NULL) && (twoIntsStructPointer->intOne == 5))
            {
                printLine("intOne == 5");
            }
        }
    }
}

void CWE476_NULL_Pointer_Dereference__binary_if_04_good()
{
    good1();
    good2();
}

#endif /* OMITGOOD */

/* Below is the main(). It is only used when building this testcase on
   its own for testing or for building a binary to use in testing binary
   analysis tools. It is not used when compiling all the testcases as one
   application, which is how source code analysis tools are tested. */

#ifdef INCLUDEMAIN

int main(int argc, char * argv[])
{
    /* seed randomness */
    srand( (unsigned)time(NULL) );
#ifndef OMITGOOD
    printLine("Calling good()...");
    CWE476_NULL_Pointer_Dereference__binary_if_04_good();
    printLine("Finished good()");
#endif /* OMITGOOD */
#ifndef OMITBAD
    printLine("Calling bad()...");
    CWE476_NULL_Pointer_Dereference__binary_if_04_bad();
    printLine("Finished bad()");
#endif /* OMITBAD */
    return 0;
}

#endif