Improve robustness when scanning PCI Option ROM.

[mirror_edk2.git] / DuetPkg / PciRootBridgeNoEnumerationDxe / Ia32 / PcatIo.c

diff --git a/DuetPkg/PciRootBridgeNoEnumerationDxe/Ia32/PcatIo.c b/DuetPkg/PciRootBridgeNoEnumerationDxe/Ia32/PcatIo.c
index 7395ce2d8b45c9ea3e2a0e87598740367ed5d9f6..fbfc2fadef5c3e586a94353c205c959b6e6cfc38 100644 (file)
--- a/DuetPkg/PciRootBridgeNoEnumerationDxe/Ia32/PcatIo.c
+++ b/DuetPkg/PciRootBridgeNoEnumerationDxe/Ia32/PcatIo.c
@@ -1,6 +1,6 @@
 /*++\r
 \r
 /*++\r
 \r

-Copyright (c) 2005 - 2008, 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
 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
 \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
             ZeroMem (&Pcir, sizeof(Pcir));\r
             IoDev->Mem.Read (\r
               IoDev, \r


@@ -447,6 +449,12 @@ CheckForRom (
               &Pcir\r
               );\r
 \r
               &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
             if ((Pcir.Indicator & 0x80) == 0x00) {\r
               LastImage = FALSE;\r
             }\r