Examples of errors detected by the V531 diagnostic

V531. The sizeof() operator is multiplied by sizeof(). Consider inspecting the expression.

XUIFramework

V531 It is odd that a sizeof() operator is multiplied by sizeof(). Borne pphtmldrawer.cpp 258

CPPString CPPHtmlDrawer::GetStringFromDll(....)
{
  ....
  TCHAR szTemp[256];

  DWORD dwLen = ::LoadString(hInstDll, dwID,
    szTemp, (sizeof(szTemp) * sizeof(TCHAR)));
  ....
}

The LoadString function takes the buffer's size in characters as the last argument. In the Unicode version of the application, we will tell the function that the buffer's size is larger than it is actually. This may cause a buffer overflow. Note that if we fix the code in the following way, it will not become correct at all: sizeof(szTemp) / sizeof(TCHAR).

Similar errors can be found in some other places:

• V531 It is odd that a sizeof() operator is multiplied by sizeof(). Borne pphtmldrawer.cpp 262

NetDefender Firewall

V531 It is odd that a sizeof() operator is multiplied by sizeof(). fire pphtmldrawer.cpp 258

CPPString CPPHtmlDrawer::GetStringFromDll(....)
{
  ....
  TCHAR szTemp[256];
  DWORD dwLen = ::LoadString(hInstDll, dwID, szTemp,
                             (sizeof(szTemp) * sizeof(TCHAR)));
  ....
}

The LoadString function takes the buffer's size in characters as the last argument. In the Unicode version of the application, we will tell the function that the buffer's size is larger than it is actually. This may cause a buffer overflow. Note that if we fix the code in the following way, it will not become correct at all: sizeof(szTemp) / sizeof(TCHAR).

ReactOS

V531 It is odd that a sizeof() operator is multiplied by sizeof(). eventvwr eventvwr.c 1112

VOID
DisplayEvent(HWND hDlg)
{
  WCHAR szEventType[MAX_PATH];
  WCHAR szTime[MAX_PATH];
  WCHAR szDate[MAX_PATH];
  ....
  ListView_GetItemText(hwndListView, iIndex, 0, szEventType,
                       sizeof(szEventType) * sizeof(WCHAR));
  ListView_GetItemText(hwndListView, iIndex, 1, szDate,
                       sizeof(szDate) * sizeof(WCHAR));
  ListView_GetItemText(hwndListView, iIndex, 2, szTime,
                       sizeof(szTime) * sizeof(WCHAR));
  ....
}

ReactOS

V531 It is odd that a sizeof() operator is multiplied by sizeof(). eventvwr.c 1117

VOID
DisplayEvent(HWND hDlg)
{
  WCHAR szEventType[MAX_PATH];
  WCHAR szTime[MAX_PATH];
  WCHAR szDate[MAX_PATH];
  WCHAR szUser[MAX_PATH];
  WCHAR szComputer[MAX_PATH];
  ....
  ListView_GetItemText(...., sizeof(szEventType)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szDate)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szTime)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szSource)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szCategory)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szEventID)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szUser)*sizeof(WCHAR));
  ListView_GetItemText(...., sizeof(szComputer)*sizeof(WCHAR));
  ....
}

Similar errors can be found in some other places:

• V531 It is odd that a sizeof() operator is multiplied by sizeof(). eventvwr.c 1118
• V531 It is odd that a sizeof() operator is multiplied by sizeof(). eventvwr.c 1119
• V531 It is odd that a sizeof() operator is multiplied by sizeof(). eventvwr.c 1120
• And 4 additional diagnostic messages.

CrashRpt library

V531 It is odd that a sizeof() operator is multiplied by sizeof(). httprequestsender.cpp 286

BOOL CHttpRequestSender::InternalSend()
{
  ....
  TCHAR szBuffer[1024]=_T("");
  DWORD dwBuffSize = sizeof(szBuffer)*sizeof(TCHAR);
  ....
}

Oracle VM Virtual Box

V531 It is odd that a sizeof() operator is multiplied by sizeof(). tstrtfileaio.cpp 61

void
tstFileAioTestReadWriteBasic(...., uint32_t cMaxReqsInFlight)
{
  /* Allocate request array. */
  RTFILEAIOREQ *paReqs;
  paReqs = (...., cMaxReqsInFlight * sizeof(RTFILEAIOREQ));
  RTTESTI_CHECK_RETV(paReqs);
  RT_BZERO(..., sizeof(cMaxReqsInFlight) * sizeof(RTFILEAIOREQ));

  /* Allocate array holding pointer to data buffers. */
  void **papvBuf = (...., cMaxReqsInFlight * sizeof(void *));
  ....
}

CMake

V531 It is odd that a sizeof() operator is multiplied by sizeof(). cmGlobalVisualStudioGenerator.cxx 558

bool IsVisualStudioMacrosFileRegistered(const std::string& macrosFile,
                                        const std::string& regKeyBase,
                                        std::string& nextAvailableSubKeyName)
{
  ....
  if (ERROR_SUCCESS == result) {
    wchar_t subkeyname[256];                                           // <=
    DWORD cch_subkeyname = sizeof(subkeyname) * sizeof(subkeyname[0]); // <=
    wchar_t keyclass[256];
    DWORD cch_keyclass = sizeof(keyclass) * sizeof(keyclass[0]);
    FILETIME lastWriteTime;
    lastWriteTime.dwHighDateTime = 0;
    lastWriteTime.dwLowDateTime = 0;

    while (ERROR_SUCCESS ==
           RegEnumKeyExW(hkey, index, subkeyname, &cch_subkeyname, 0, keyclass,
                         &cch_keyclass, &lastWriteTime)) {
    ....
  }
  ....
}

Similar errors can be found in some other places:

• V531 It is odd that a sizeof() operator is multiplied by sizeof(). cmGlobalVisualStudioGenerator.cxx 556
• V531 It is odd that a sizeof() operator is multiplied by sizeof(). cmGlobalVisualStudioGenerator.cxx 572
• V531 It is odd that a sizeof() operator is multiplied by sizeof(). cmGlobalVisualStudioGenerator.cxx 621
• And 2 additional diagnostic messages.

GPCS4

V531 [CWE-131] It is odd that a sizeof() operator is multiplied by sizeof(). sce_gnm_draw.cpp 420

struct GnmCmdPSShader
{
  ....
  uint32_t              reserved[27];
};

int PS4API sceGnmSetPsShader350(....)
{
  ....
  memset(param->reserved, 0, sizeof(param->reserved) * sizeof(uint32_t));
  return SCE_OK;
}