From 5cabd6269f88ffb257ea78d1b93d8c3ac952bb71 Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Sun, 27 Apr 2014 18:46:26 +0000
Subject: [PATCH] [NTOSKRNL] Fix potential overflows

CID #701302
CID #1206856

svn path=/trunk/; revision=63023
---
 reactos/ntoskrnl/fstub/fstubex.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/reactos/ntoskrnl/fstub/fstubex.c b/reactos/ntoskrnl/fstub/fstubex.c
index e864c1f09cd..d039e718b1c 100644
--- a/reactos/ntoskrnl/fstub/fstubex.c
+++ b/reactos/ntoskrnl/fstub/fstubex.c
@@ -1006,7 +1006,7 @@ FstubReadPartitionTableEFI(IN PDISK_INFORMATION Disk,
         if ((Disk->SectorCount - 1ULL) != EfiHeader->AlternateLBA)
         {
             /* We'll update it. First, count number of sectors needed to store partitions */
-            SectorsForPartitions = (EfiHeader->NumberOfEntries * PARTITION_ENTRY_SIZE) / Disk->SectorSize;
+            SectorsForPartitions = ((ULONGLONG)EfiHeader->NumberOfEntries * PARTITION_ENTRY_SIZE) / Disk->SectorSize;
             /* Then set first usable LBA: Legacy MBR + GPT header + Partitions entries */
             EfiHeader->FirstUsableLBA = SectorsForPartitions + 2;
             /* Then set last usable LBA: Last sector - GPT header - Partitions entries */
@@ -1313,7 +1313,7 @@ FstubVerifyPartitionTableEFI(IN PDISK_INFORMATION Disk,
     }
 
     /* Compute sectors taken by partitions */
-    SectorsForPartitions = ((EFIHeader->NumberOfEntries * PARTITION_ENTRY_SIZE) + Disk->SectorSize - 1) / Disk->SectorSize;
+    SectorsForPartitions = (((ULONGLONG)EFIHeader->NumberOfEntries * PARTITION_ENTRY_SIZE) + Disk->SectorSize - 1) / Disk->SectorSize;
     if (PrimaryValid)
     {
         WriteBackup = TRUE;