From 288997968e9c6352b09930c23fc05f53e3bc0dad Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Fri, 22 Mar 2019 21:53:23 +0100
Subject: [PATCH 7/8] MdeModulePkg/UdfDxe: Add boundary check for getting
 volume (free) size
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Message-id: <20190322205323.17693-6-lersek@redhat.com>
Patchwork-id: 85134
O-Subject:  [RHEL-7.7 ovmf PATCH 5/5] MdeModulePkg/UdfDxe: Add boundary check for
	getting volume (free) size
Bugzilla: 1691647
Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>

From: Hao Wu <hao.a.wu@intel.com>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=828

Within GetVolumeSize():

The boundary check will validate the 'NumberOfPartitions' field of a
Logical Volume Integrity Descriptor matches the data within the relating
Logical Volume Descriptor.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Acked-by: Star Zeng <star.zeng@intel.com>
(cherry picked from commit 3b30351b75d70ea65701ac999875fbb81a89a5ca)
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 .../Universal/Disk/UdfDxe/FileSystemOperations.c        | 17 ++++++++++++++++-
 MdeModulePkg/Universal/Disk/UdfDxe/Udf.h                |  7 +++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
index 1aefed8..ae19a42 100644
--- a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
@@ -2451,6 +2451,13 @@ SetFileInfo (
 /**
   Get volume and free space size information of an UDF volume.
 
+  @attention This is boundary function that may receive untrusted input.
+  @attention The input is from FileSystem.
+
+  The Logical Volume Descriptor and the Logical Volume Integrity Descriptor are
+  external inputs, so this routine will do basic validation for both descriptors
+  and report status.
+
   @param[in]   BlockIo        BlockIo interface.
   @param[in]   DiskIo         DiskIo interface.
   @param[in]   Volume         UDF volume information structure.
@@ -2489,7 +2496,8 @@ GetVolumeSize (
 
   ExtentAd = &LogicalVolDesc->IntegritySequenceExtent;
 
-  if (ExtentAd->ExtentLength == 0) {
+  if ((ExtentAd->ExtentLength == 0) ||
+      (ExtentAd->ExtentLength < sizeof (UDF_LOGICAL_VOLUME_INTEGRITY))) {
     return EFI_VOLUME_CORRUPTED;
   }
 
@@ -2529,6 +2537,13 @@ GetVolumeSize (
     goto Out_Free;
   }
 
+  if ((LogicalVolInt->NumberOfPartitions > MAX_UINT32 / sizeof (UINT32) / 2) ||
+      (LogicalVolInt->NumberOfPartitions * sizeof (UINT32) * 2 >
+       ExtentAd->ExtentLength - sizeof (UDF_LOGICAL_VOLUME_INTEGRITY))) {
+    Status = EFI_VOLUME_CORRUPTED;
+    goto Out_Free;
+  }
+
   *VolumeSize = 0;
   *FreeSpaceSize = 0;
 
diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/Udf.h b/MdeModulePkg/Universal/Disk/UdfDxe/Udf.h
index 9b82441..b054c62 100644
--- a/MdeModulePkg/Universal/Disk/UdfDxe/Udf.h
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/Udf.h
@@ -903,6 +903,13 @@ SetFileInfo (
 /**
   Get volume and free space size information of an UDF volume.
 
+  @attention This is boundary function that may receive untrusted input.
+  @attention The input is from FileSystem.
+
+  The Logical Volume Descriptor and the Logical Volume Integrity Descriptor are
+  external inputs, so this routine will do basic validation for both descriptors
+  and report status.
+
   @param[in]   BlockIo        BlockIo interface.
   @param[in]   DiskIo         DiskIo interface.
   @param[in]   Volume         UDF volume information structure.
-- 
1.8.3.1