CERT.FILE_PTR.DEREF.INDIRECT
A pointer to a FILE object shall not be indirectly dereferenced by a system function, for example, by a call to memcpy or memcmp.
Vulnerability and risk
An indirect dereference of a pointer to a FILE object by a system function, for example, by a call to memcpy or memcmp, may result in unexpected behavior.
Mitigation and prevention
Do not dereference a pointer to a FILE object indirectly by using a system function.
Vulnerable code example
Copy
#include <cstring>
#include <wchar.h>
#include <iostream>
typedef FILE file4;
typedef file4 file3;
typedef file3 file2;
typedef file2 file;
file *pf1;
#define FILE_ALIAS FILE
FILE_ALIAS *pf2;
typedef FILE *file_pointer;
file_pointer pf3;
typedef int *int_alias2;
typedef int_alias2 int_alias1;
typedef int_alias1 int_alias;
int_alias pf4;
void func5_memcpy_function ( void )
{
memset((void *)pf1, '-', 0);
memset((void *)pf2, '-', 0);
wmemset((void *)pf3, '-', 0);
memset((void *)pf4, '-', 0);
memset((void*)pf1, '-', 9);
memset((void *)pf2, '-', 9);
memset((void *)pf4, '-', 9);
}In this noncompliant example, Klocwork reports a CERT.FILE_PTR.DEREF.INDIRECT on lines 30 and 31, because indirectly dereferencing a pointer to a FILE object by using a system function ‘memcpy’, may result in unexpected behavior.
Fixed code example
Copy
#include <cstring>
#include <wchar.h>
#include <iostream>
typedef FILE file4;
typedef file4 file3;
typedef file3 file2;
typedef file2 file;
file pf1;
#define FILE_ALIAS FILE
FILE_ALIAS pf2;
typedef FILE file_pointer;
file_pointer pf3;
typedef int *int_alias2;
typedef int_alias2 int_alias1;
typedef int_alias1 int_alias;
int_alias pf4;
void func5_memcpy_function ( void )
{
memset((void *)pf1, '-', 0);
memset((void *)pf2, '-', 0);
wmemset((void *)pf3, '-', 0);
memset((void *)pf4, '-', 0);
memset((void *)pf4, '-', 9);
}The above example is compliant because no system function is used to dereference a pointer to a FILE object.
Related checkers
- MISRA.FILE_PTR.DEREF.INDIRECT.2012