FatPkg: Fix EnhancedFatDxe driver coverity issues

[Ranbir.Singh3@Dell.com]

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Hi All,

Attached patch contains the changes fixing the issues pointed by Coverity scan on FatPkg component.

Please review if the changes are safe to be considered.

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From 2be2f147b1193a15b6aac7e231c67ff318fcb9ee Mon Sep 17 00:00:00 2001
From: Ranbir Singh <Ranbir.Singh3@Dell.com>
Date: Wed, 21 Dec 2022 16:53:29 +0530
Subject: [PATCH] FatPkg: Fix EnhancedFatDxe driver coverity issues

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4199

Use proper typecast to avoid SIGN_EXTENSION and OVERFLOW_BEFORE_WIDEN.

Signed-off-by: Ranbir Singh <Ranbir.Singh3@Dell.com>
---
 FatPkg/EnhancedFatDxe/DirectoryManage.c | 4 ++--
 FatPkg/EnhancedFatDxe/DiskCache.c       | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/FatPkg/EnhancedFatDxe/DirectoryManage.c b/FatPkg/EnhancedFatDxe/DirectoryManage.c
index 723fc35f38..cc4acfec2f 100644
--- a/FatPkg/EnhancedFatDxe/DirectoryManage.c
+++ b/FatPkg/EnhancedFatDxe/DirectoryManage.c
@@ -474,7 +474,7 @@ FatGetDirEntInfo (
     Info       = Buffer;
     Info->Size = ResultSize;
     if ((Entry->Attributes & FAT_ATTRIBUTE_DIRECTORY) != 0) {
-      Cluster            = (Entry->FileClusterHigh << 16) | Entry->FileCluster;
+      Cluster            = ((UINTN)(Entry->FileClusterHigh) << 16) | (UINTN)Entry->FileCluster;
       Info->PhysicalSize = FatPhysicalDirSize (Volume, Cluster);
       Info->FileSize     = Info->PhysicalSize;
     } else {
@@ -1167,7 +1167,7 @@ FatOpenDirEnt (
       //
       Volume             = Parent->Volume;
       OFile->FullPathLen = Parent->FullPathLen + 1 + StrLen (DirEnt->FileString);
-      OFile->FileCluster = ((DirEnt->Entry.FileClusterHigh) << 16) | (DirEnt->Entry.FileCluster);
+      OFile->FileCluster = (((UINTN)(DirEnt->Entry.FileClusterHigh)) << 16) | (DirEnt->Entry.FileCluster);
       InsertTailList (&Parent->ChildHead, &OFile->ChildLink);
     } else {
       //
diff --git a/FatPkg/EnhancedFatDxe/DiskCache.c b/FatPkg/EnhancedFatDxe/DiskCache.c
index d1a34a6a64..d56e338586 100644
--- a/FatPkg/EnhancedFatDxe/DiskCache.c
+++ b/FatPkg/EnhancedFatDxe/DiskCache.c
@@ -477,7 +477,7 @@ FatInitializeDiskCache (
   DiskCache[CacheFat].BaseAddress   = Volume->FatPos;
   DiskCache[CacheFat].LimitAddress  = Volume->FatPos + Volume->FatSize;
   FatCacheSize                      = FatCacheGroupCount << DiskCache[CacheFat].PageAlignment;
-  DataCacheSize                     = FAT_DATACACHE_GROUP_COUNT << DiskCache[CacheData].PageAlignment;
+  DataCacheSize                     = (UINTN)FAT_DATACACHE_GROUP_COUNT << DiskCache[CacheData].PageAlignment;
   //
   // Allocate the Fat Cache buffer
   //
-- 
2.36.1.windows.1