[edk2-platforms][PATCH v1 09/12] Ext4Pkg: Correct integer overflow check on multiplication in DiskUtil

["Savva Mitrofanov" <savvamtr@gmail.com>]

Multiplication overflow could result into small numbers, so we need also
check it

Cc: Marvin Häuser <mhaeuser@posteo.de>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vitaly Cheptsov <vit9696@protonmail.com>
Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
---
 Features/Ext4Pkg/Ext4Pkg.dsc        | 2 +-
 Features/Ext4Pkg/Ext4Dxe/DiskUtil.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Features/Ext4Pkg/Ext4Pkg.dsc b/Features/Ext4Pkg/Ext4Pkg.dsc
index 59bc327ebf6e..621c63eaf92d 100644
--- a/Features/Ext4Pkg/Ext4Pkg.dsc
+++ b/Features/Ext4Pkg/Ext4Pkg.dsc
@@ -46,7 +46,7 @@
   DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
   OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
   BaseUcs2Utf8Lib|RedfishPkg/Library/BaseUcs2Utf8Lib/BaseUcs2Utf8Lib.inf
-  
+
   #
   # Required for stack protector support
   #
diff --git a/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c b/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
index 32da35f7d9f5..c4af956da926 100644
--- a/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
+++ b/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
@@ -60,11 +60,11 @@ Ext4ReadBlocks (
   // Check for overflow on the block -> byte conversions.
   // Partition->BlockSize is never 0, so we don't need to check for that.
 
-  if (Offset > DivU64x32 ((UINT64)-1, Partition->BlockSize)) {
+  if ((NumberBlocks != 0) && (DivU64x64Remainder (Offset, BlockNumber, NULL) != Partition->BlockSize)) {
     return EFI_INVALID_PARAMETER;
   }
 
-  if (Length > (UINTN)-1/Partition->BlockSize) {
+  if ((NumberBlocks != 0) && (Length / NumberBlocks != Partition->BlockSize)) {
     return EFI_INVALID_PARAMETER;
   }
 
@@ -94,12 +94,12 @@ Ext4AllocAndReadBlocks (
 
   Length = NumberBlocks * Partition->BlockSize;
 
-  if (Length > (UINTN)-1/Partition->BlockSize) {
+  // Check for integer overflow
+  if ((NumberBlocks != 0) && (Length / NumberBlocks != Partition->BlockSize)) {
     return NULL;
   }
 
   Buf = AllocatePool (Length);
-
   if (Buf == NULL) {
     return NULL;
   }
-- 
2.38.1