MdeModulePkg/UdfDxe: Refine boundary checks for file/path name string

[mirror_edk2.git] / MdeModulePkg / Universal / Disk / UdfDxe / File.c

diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/File.c b/MdeModulePkg/Universal/Disk/UdfDxe/File.c
index 2249f4ea0e8e566f3fc67d8a81d8985bb3d4fc4b..4aa0594f1a9e9d87f3252382b91714bb75efa611 100644 (file)
--- a/MdeModulePkg/Universal/Disk/UdfDxe/File.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/File.c
@@ -2,6 +2,7 @@
   Handle operations in files and directories from UDF/ECMA-167 file systems.\r
 \r
   Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>\r
+  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials are licensed and made available\r
   under the terms and conditions of the BSD License which accompanies this\r
@@ -248,7 +249,7 @@ UdfOpen (
     FileName = TempFileName + 1;\r
   }\r
 \r
-  StrCpyS (NewPrivFileData->FileName, UDF_PATH_LENGTH, FileName);\r
+  StrCpyS (NewPrivFileData->FileName, UDF_FILENAME_LENGTH, FileName);\r
 \r
   Status = GetFileSize (\r
     PrivFsData->BlockIo,\r
@@ -257,8 +258,12 @@ UdfOpen (
     &NewPrivFileData->File,\r
     &NewPrivFileData->FileSize\r
     );\r
-  ASSERT_EFI_ERROR (Status);\r
   if (EFI_ERROR (Status)) {\r
+    DEBUG ((\r
+      DEBUG_ERROR,\r
+      "%a: GetFileSize() fails with status - %r.\n",\r
+      __FUNCTION__, Status\r
+      ));\r
     goto Error_Get_File_Size;\r
   }\r
 \r
@@ -453,7 +458,7 @@ UdfRead (
       FreePool ((VOID *)NewFileEntryData);\r
       NewFileEntryData = FoundFile.FileEntry;\r
 \r
-      Status = GetFileNameFromFid (NewFileIdentifierDesc, FileName);\r
+      Status = GetFileNameFromFid (NewFileIdentifierDesc, ARRAY_SIZE (FileName), FileName);\r
       if (EFI_ERROR (Status)) {\r
         FreePool ((VOID *)FoundFile.FileIdentifierDesc);\r
         goto Error_Get_FileName;\r
@@ -465,7 +470,7 @@ UdfRead (
       FoundFile.FileIdentifierDesc  = NewFileIdentifierDesc;\r
       FoundFile.FileEntry           = NewFileEntryData;\r
 \r
-      Status = GetFileNameFromFid (FoundFile.FileIdentifierDesc, FileName);\r
+      Status = GetFileNameFromFid (FoundFile.FileIdentifierDesc, ARRAY_SIZE (FileName), FileName);\r
       if (EFI_ERROR (Status)) {\r
         goto Error_Get_FileName;\r
       }\r
@@ -496,6 +501,10 @@ UdfRead (
     PrivFileData->FilePosition++;\r
     Status = EFI_SUCCESS;\r
   } else if (IS_FID_DELETED_FILE (Parent->FileIdentifierDesc)) {\r
+    //\r
+    // Code should never reach here.\r
+    //\r
+    ASSERT (FALSE);\r
     Status = EFI_DEVICE_ERROR;\r
   }\r
 \r
@@ -727,6 +736,12 @@ UdfSetPosition (
 /**\r
   Get information about a file.\r
 \r
+  @attention This is boundary function that may receive untrusted input.\r
+  @attention The input is from FileSystem.\r
+\r
+  The File Set Descriptor is external input, so this routine will do basic\r
+  validation for File Set Descriptor and report status.\r
+\r
   @param  This            Protocol instance pointer.\r
   @param  InformationType Type of information to return in Buffer.\r
   @param  BufferSize      On input size of buffer, on output amount of data in\r
@@ -803,6 +818,10 @@ UdfGetInfo (
         *String = *(UINT8 *)(OstaCompressed + Index) << 8;\r
         Index++;\r
       } else {\r
+        if (Index > ARRAY_SIZE (VolumeLabel)) {\r
+          return EFI_VOLUME_CORRUPTED;\r
+        }\r
+\r
         *String = 0;\r
       }\r
 \r
@@ -822,7 +841,11 @@ UdfGetInfo (
       String++;\r
     }\r
 \r
-    *String = L'\0';\r
+    Index = ((UINTN)String - (UINTN)VolumeLabel) / sizeof (CHAR16);\r
+    if (Index > ARRAY_SIZE (VolumeLabel) - 1) {\r
+      Index = ARRAY_SIZE (VolumeLabel) - 1;\r
+    }\r
+    VolumeLabel[Index] = L'\0';\r
 \r
     FileSystemInfoLength = StrSize (VolumeLabel) +\r
                            sizeof (EFI_FILE_SYSTEM_INFO);\r
@@ -832,8 +855,11 @@ UdfGetInfo (
     }\r
 \r
     FileSystemInfo = (EFI_FILE_SYSTEM_INFO *)Buffer;\r
-    StrCpyS (FileSystemInfo->VolumeLabel, ARRAY_SIZE (VolumeLabel),\r
-             VolumeLabel);\r
+    StrCpyS (\r
+      FileSystemInfo->VolumeLabel,\r
+      (*BufferSize - OFFSET_OF (EFI_FILE_SYSTEM_INFO, VolumeLabel)) / sizeof (CHAR16),\r
+      VolumeLabel\r
+      );\r
     Status = GetVolumeSize (\r
       PrivFsData->BlockIo,\r
       PrivFsData->DiskIo,\r