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* [PATCH] CryptoPkg/BaseCryptLib: Fix potential integer overflow issue.
@ 2018-10-24 13:22 Long Qin
  2018-10-24 16:59 ` Laszlo Ersek
  2018-10-26  0:50 ` Ye, Ting
  0 siblings, 2 replies; 4+ messages in thread
From: Long Qin @ 2018-10-24 13:22 UTC (permalink / raw)
  To: edk2-devel; +Cc: ting.ye

The LookupFreeMemRegion() in RuntimeMemAllocate.c is used to look-up
free memory region for runtime resource allocation, which was designed
to support runtime authenticated variable service.
The direct offset subtractions in this function may bring possible
integer overflow issue.

This patch is to add the extra parameter checks to remove this possible
overflow risk.

Cc: Ye Ting <ting.ye@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Long Qin <qin.long@intel.com>
---
 .../Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c    | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c b/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
index 463f2bf855..92bb9ddccd 100644
--- a/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
+++ b/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
@@ -2,7 +2,7 @@
   Light-weight Memory Management Routines for OpenSSL-based Crypto
   Library at Runtime Phase.
 
-Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -141,6 +141,12 @@ LookupFreeMemRegion (
 
   StartPageIndex = RT_SIZE_TO_PAGES (mRTPageTable->LastEmptyPageOffset);
   ReqPages       = RT_SIZE_TO_PAGES (AllocationSize);
+  if (ReqPages > mRTPageTable->PageCount) {
+    //
+    // No enough region for object allocation.
+    //
+    return (UINTN)(-1);
+  }
 
   //
   // Look up the free memory region with in current memory map table.
@@ -176,6 +182,12 @@ LookupFreeMemRegion (
   // Look up the free memory region from the beginning of the memory table
   // until the StartCursorOffset
   //
+  if (ReqPages > StartPageIndex) {
+    //
+    // No enough region for object allocation.
+    //
+    return (UINTN)(-1);
+  }
   for (Index = 0; Index < (StartPageIndex - ReqPages); ) {
     //
     // Check Consecutive ReqPages Pages.
-- 
2.16.1.windows.1



^ permalink raw reply related	[flat|nested] 4+ messages in thread

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Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2018-10-24 13:22 [PATCH] CryptoPkg/BaseCryptLib: Fix potential integer overflow issue Long Qin
2018-10-24 16:59 ` Laszlo Ersek
2018-10-25 13:23   ` Long, Qin
2018-10-26  0:50 ` Ye, Ting

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