Improve robustness when scanning PCI Option ROM.

[mirror_edk2.git] / DuetPkg / PciRootBridgeNoEnumerationDxe / X64 / PcatIo.c

diff --git a/DuetPkg/PciRootBridgeNoEnumerationDxe/X64/PcatIo.c b/DuetPkg/PciRootBridgeNoEnumerationDxe/X64/PcatIo.c
index 5320f560d9f4f07ee2e8607783fb6f5d18c379d2..1e4c218032b6393680c3e37df9853bee07269d1e 100644 (file)
--- a/DuetPkg/PciRootBridgeNoEnumerationDxe/X64/PcatIo.c
+++ b/DuetPkg/PciRootBridgeNoEnumerationDxe/X64/PcatIo.c
@@ -1,6 +1,6 @@
 /*++\r
 \r
-Copyright (c) 2005 - 2006, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2005 - 2012, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials                          \r
 are licensed and made available under the terms and conditions of the BSD License         \r
 which accompanies this distribution.  The full text of the license may be found at        \r
@@ -436,8 +436,10 @@ CheckForRom (
 \r
           Pcir.ImageLength = 0;\r
 \r
-          if (EfiRomHeader.Signature == 0xaa55) {\r
-\r
+          if (EfiRomHeader.Signature == PCI_EXPANSION_ROM_HEADER_SIGNATURE &&\r
+              EfiRomHeader.PcirOffset != 0 &&\r
+              (EfiRomHeader.PcirOffset & 3) == 0 &&\r
+              RomBarSize + EfiRomHeader.PcirOffset + sizeof (PCI_DATA_STRUCTURE) <= MaxRomSize) {\r
             ZeroMem (&Pcir, sizeof(Pcir));\r
             IoDev->Mem.Read (\r
               IoDev, \r
@@ -447,6 +449,12 @@ CheckForRom (
               &Pcir\r
               );\r
 \r
+            if (Pcir.Signature != PCI_DATA_STRUCTURE_SIGNATURE) {\r
+              break;\r
+            }\r
+            if (RomBarSize + Pcir.ImageLength * 512 > MaxRomSize) {\r
+              break;\r
+            }\r
             if ((Pcir.Indicator & 0x80) == 0x00) {\r
               LastImage = FALSE;\r
             }\r