MdeModulePkg: Fix missing NULL tests

https://github.com/github/codeql/blob/codeql-cli-2.7.3/cpp/ql/src/Critical/MissingNullTest.qhelp

For items which allocate memory, or get a pointer from another
structure, it is important to validate that the pointers
are not null before they are dereferenced.

Signed-off-by: Aaron Pop <aaronpop@microsoft.com>

5 files changed, 55 insertions, 10 deletions

diff --git a/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c b/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
index 5ce5a50f7b..f1501ebcf4 100644
--- a/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
+++ b/MdeModulePkg/Application/CapsuleApp/CapsuleOnDisk.c
@@ -518,7 +518,11 @@ GetUpdateFileSystem (
     // If map is assigned, try to get ESP from mapped Fs.

     //

     DevicePath = DuplicateDevicePath (MappedDevicePath);

-    Status     = GetEfiSysPartitionFromDevPath (DevicePath, &FullPath, Fs);

+    if (DevicePath == NULL) {

+      return EFI_OUT_OF_RESOURCES;

+    }

+

+    Status = GetEfiSysPartitionFromDevPath (DevicePath, &FullPath, Fs);

     if (EFI_ERROR (Status)) {

       Print (L"Error: Cannot get EFI system partition from '%s' - %r\n", Map, Status);

       return EFI_NOT_FOUND;

diff --git a/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c b/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
index 68c2e35791..18415c056e 100644
--- a/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
+++ b/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
@@ -610,7 +610,12 @@ DumpSmiHandler (
 

         Print (L">\n");

         ImageStruct = GetImageFromRef ((UINTN)SmiHandlerStruct->ImageRef);

-        NameString  = GetDriverNameString (ImageStruct);

+        if (ImageStruct != NULL) {

+          NameString = GetDriverNameString (ImageStruct);

+        } else {

+          NameString = "\0";

+        }

+

         Print (L"      <Module RefId=\"0x%x\" Name=\"%a\">\n", SmiHandlerStruct->ImageRef, NameString);

         if ((ImageStruct != NULL) && (ImageStruct->PdbStringOffset != 0)) {

           Print (L"      <Pdb>%a</Pdb>\n", (UINT8 *)ImageStruct + ImageStruct->PdbStringOffset);

diff --git a/MdeModulePkg/Application/UiApp/FrontPage.c b/MdeModulePkg/Application/UiApp/FrontPage.c
index 56e174fe56..84fba400a2 100644
--- a/MdeModulePkg/Application/UiApp/FrontPage.c
+++ b/MdeModulePkg/Application/UiApp/FrontPage.c
@@ -203,10 +203,17 @@ UpdateFrontPageForm (
   // Allocate space for creation of UpdateData Buffer

   //

   StartOpCodeHandle = HiiAllocateOpCodeHandle ();

-  ASSERT (StartOpCodeHandle != NULL);

+  if (StartOpCodeHandle == NULL) {

+    ASSERT (StartOpCodeHandle != NULL);

+    return;

+  }

 

   EndOpCodeHandle = HiiAllocateOpCodeHandle ();

-  ASSERT (EndOpCodeHandle != NULL);

+  if (EndOpCodeHandle == NULL) {

+    ASSERT (EndOpCodeHandle != NULL);

+    goto Exit;

+  }

+

   //

   // Create Hii Extend Label OpCode as the start opcode

   //

@@ -236,8 +243,10 @@ UpdateFrontPageForm (
     EndOpCodeHandle

     );

 

-  HiiFreeOpCodeHandle (StartOpCodeHandle);

   HiiFreeOpCodeHandle (EndOpCodeHandle);

+Exit:

+  HiiFreeOpCodeHandle (StartOpCodeHandle);

+  return;

 }

 

 /**

@@ -966,7 +975,10 @@ InitializeUserInterface (
   // Install customized fonts needed by Front Page

   //

   HiiHandle = ExportFonts ();

-  ASSERT (HiiHandle != NULL);

+  if (HiiHandle == NULL) {

+    ASSERT (HiiHandle != NULL);

+    return EFI_NOT_FOUND;

+  }

 

   InitializeStringSupport ();

 

diff --git a/MdeModulePkg/Application/UiApp/FrontPageCustomizedUiSupport.c b/MdeModulePkg/Application/UiApp/FrontPageCustomizedUiSupport.c
index 24f9f1e3fb..ef6b527d18 100644
--- a/MdeModulePkg/Application/UiApp/FrontPageCustomizedUiSupport.c
+++ b/MdeModulePkg/Application/UiApp/FrontPageCustomizedUiSupport.c
@@ -191,6 +191,11 @@ UiSupportLibCallbackHandler (
 

   if (Action == EFI_BROWSER_ACTION_RETRIEVE) {

     if (QuestionId == FRONT_PAGE_KEY_LANGUAGE) {

+      if (Value == NULL) {

+        *Status = EFI_INVALID_PARAMETER;

+        return FALSE;

+      }

+

       Value->u8 = gCurrentLanguageIndex;

       *Status   = EFI_SUCCESS;

     } else {

@@ -346,7 +351,10 @@ UiCreateLanguageMenu (
   OptionCount = 0;

   if (Lang == NULL) {

     Lang = AllocatePool (AsciiStrSize (gLanguageString));

-    ASSERT (Lang != NULL);

+    if (Lang == NULL) {

+      ASSERT (Lang != NULL);

+      goto Exit;

+    }

   }

 

   while (*LangCode != 0) {

@@ -393,6 +401,7 @@ UiCreateLanguageMenu (
     NULL

     );

 

+Exit:

   HiiFreeOpCodeHandle (OptionsOpCodeHandle);

 }

 

@@ -592,10 +601,20 @@ UiListThirdPartyDrivers (
   }

 

   HiiHandles = HiiGetHiiHandles (NULL);

-  ASSERT (HiiHandles != NULL);

+  if ( HiiHandles == NULL) {

+    ASSERT (HiiHandles != NULL);

+    DEBUG ((DEBUG_ERROR, "%a No HII handles found in the HII database\n", __func__));

+    return EFI_NOT_FOUND;

+  }

 

   gHiiDriverList = AllocateZeroPool (UI_HII_DRIVER_LIST_SIZE * sizeof (UI_HII_DRIVER_INSTANCE));

-  ASSERT (gHiiDriverList != NULL);

+  if (gHiiDriverList == NULL) {

+    ASSERT (gHiiDriverList != NULL);

+    DEBUG ((DEBUG_VERBOSE, "%a No memory for gHiiDriverList\n", __func__));

+    FreePool (HiiHandles);

+    return EFI_OUT_OF_RESOURCES;

+  }

+

   DriverListPtr = gHiiDriverList;

   CurrentSize   = UI_HII_DRIVER_LIST_SIZE;

 

diff --git a/MdeModulePkg/Application/VariableInfo/VariableInfo.c b/MdeModulePkg/Application/VariableInfo/VariableInfo.c
index 3dee41eb4b..13c4acc2f2 100644
--- a/MdeModulePkg/Application/VariableInfo/VariableInfo.c
+++ b/MdeModulePkg/Application/VariableInfo/VariableInfo.c
@@ -131,7 +131,12 @@ PrintInfoFromSmm (
     Entry = (EFI_MEMORY_DESCRIPTOR *)((UINT8 *)Entry + PiSmmCommunicationRegionTable->DescriptorSize);

   }

 

-  ASSERT (CommBuffer != NULL);

+  if (CommBuffer == NULL) {

+    DEBUG ((DEBUG_ERROR, "Warning: No SMM communication buffer found!\n"));

+    ASSERT (CommBuffer != NULL);

+    return EFI_NOT_FOUND;

+  }

+

   ZeroMem (CommBuffer, RealCommSize);

 

   Print (L"SMM Driver Non-Volatile Variables:\n");