uefi_fv: Minor fixes

- Add additional error handling for LZMA-compressed GUID-defined sections - Parse UEFI firmware volume extended headers
al3xtjames · Jul 22, 2019 · c81a34e · c81a34e
1 parent e169fe4
commit c81a34e
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Showing 2 changed files with 42 additions and 21 deletions.
diff --git a/src/main/java/firmware/uefi_fv/FFSGUIDDefinedSection.java b/src/main/java/firmware/uefi_fv/FFSGUIDDefinedSection.java
@@ -100,13 +100,20 @@ public FFSGUIDDefinedSection(BinaryReader reader, UEFIFirmwareVolumeFileSystem f
 				reader.getByteProvider().getInputStream(reader.getPointerIndex()),
 				length());
 
-			LZMACompressorInputStream inputStream = new LZMACompressorInputStream(boundedStream);
-			uncompressedData = inputStream.readAllBytes();
+			try {
+				LZMACompressorInputStream inputStream = new LZMACompressorInputStream(boundedStream);
+				uncompressedData = inputStream.readAllBytes();
 
-			// Parse the uncompressed section.
-			BinaryReader sectionReader = new BinaryReader(
-				new ByteArrayProvider(uncompressedData), true);
-			parseNestedSections(sectionReader, uncompressedData.length, fs, fileImpl);
+				// Parse the uncompressed section.
+				BinaryReader sectionReader = new BinaryReader(
+					new ByteArrayProvider(uncompressedData), true);
+				parseNestedSections(sectionReader, uncompressedData.length, fs, fileImpl);
+			} catch (IOException e) {
+				Msg.error(this, "Failed to extract LZMA compressed section: " +
+						e.getMessage());
+				reader.setPointerIndex(baseIndex + getTotalLength());
+				return;
+			}
 		} else {
 			// Parse the data in the current GUID-defined section.
 			parseNestedSections(reader, length(), fs, fileImpl);

diff --git a/src/main/java/firmware/uefi_fv/UEFIFirmwareVolumeHeader.java b/src/main/java/firmware/uefi_fv/UEFIFirmwareVolumeHeader.java
@@ -57,6 +57,17 @@
  *   | u32  |    4 | Block Size       |
  *   +------+------+------------------+
  *
+ * The Extended Header Offset field is relative to the start of firmware volume header; it has the
+ * following structure:
+ *
+ *   UEFI Firmware Volume Extended Header
+ *   +------------+------+----------------------+
+ *   | Type       | Size | Description          |
+ *   +------------+------+----------------------+
+ *   | efi_guid_t |   16 | Firmware Volume Name |
+ *   | u32        |    4 | Extended Header Size |
+ *   +------------+------+----------------------+
+ *
  * Each firmware volume contains a number of UEFI Firmware File System (FFS) files, which may be
  * aligned depending on the bits set in the Attributes field of the UEFI Firmware Volume header.
  * See UFSIFFSFile and UEFIFFSv3File for information regarding the FFS file header fields.
@@ -73,6 +84,10 @@ public class UEFIFirmwareVolumeHeader implements UEFIFile {
 	private short extendedHeaderOffset;
 	private byte revision;
 
+	// Extended header fields
+	private UUID fvName;
+	private int extendedHeaderSize;
+
 	private long baseIndex;
 
 	/**
@@ -90,7 +105,7 @@ public UEFIFirmwareVolumeHeader(BinaryReader reader, UEFIFirmwareVolumeFileSyste
 
 		fileSystemGuid = UUIDUtils.fromBinaryReader(reader);
 		size = reader.readNextLong();
-		if (size <= UEFIFirmwareVolumeConstants.UEFI_FV_HEADER_SIZE) {
+		if (size < UEFIFirmwareVolumeConstants.UEFI_FV_HEADER_SIZE) {
 			throw new IOException("Not a valid UEFI FV header");
 		}
 
@@ -112,11 +127,11 @@ public UEFIFirmwareVolumeHeader(BinaryReader reader, UEFIFirmwareVolumeFileSyste
 		// Skip the FvBlockMap field.
 		reader.setPointerIndex(reader.getPointerIndex() + 16);
 
+		// Read the extended header fields (if present).
 		if (revision == 2 && extendedHeaderOffset > 0) {
-			// The extended header structure consists of a EFI GUID followed by the size of the
-			// header (stored as u32).
-			reader.setPointerIndex(baseIndex + extendedHeaderOffset + 16);
-			int extendedHeaderSize = reader.readNextInt();
+			reader.setPointerIndex(baseIndex + extendedHeaderOffset);
+			fvName = UUIDUtils.fromBinaryReader(reader);
+			extendedHeaderSize = reader.readNextInt();
 			reader.setPointerIndex(baseIndex + extendedHeaderOffset + extendedHeaderSize);
 		}
 
@@ -155,7 +170,6 @@ public UEFIFirmwareVolumeHeader(BinaryReader reader, UEFIFirmwareVolumeFileSyste
 					reader.align(8);
 				}
 
-				long originalIndex = reader.getPointerIndex();
 				try {
 					UEFIFFSFile file = new UEFIFFSFile(reader, fs, fileImpl);
 				} catch (IOException e) {
@@ -168,21 +182,16 @@ public UEFIFirmwareVolumeHeader(BinaryReader reader, UEFIFirmwareVolumeFileSyste
 		reader.setPointerIndex(baseIndex + size);
 	}
 
-	/**
-	 * Returns the file system GUID for the current firmware volume.
-	 *
-	 * @return the file system GUID for the current firmware volume
-	 */
-	public UUID getGUID() {
-		return fileSystemGuid;
-	}
-
 	/**
 	 * Returns the name of the current firmware volume.
 	 *
 	 * @return the name of the current firmware volume
 	 */
 	public String getName() {
+		if (fvName != null) {
+			return UUIDUtils.getName(fvName);
+		}
+
 		return UUIDUtils.getName(fileSystemGuid);
 	}
 
@@ -209,6 +218,11 @@ public String toString() {
 		formatter.format("Firmware volume attributes: 0x%X\n", attributes);
 		formatter.format("Firmware volume header size: 0x%X\n", headerSize);
 		formatter.format("Firmware volume revision: %d", revision);
+		if (revision == 2 && extendedHeaderOffset > 0) {
+			formatter.format("\nFirmware volume name GUID: %s\n", fvName.toString());
+			formatter.format("Firmware volume extended header size: 0x%X", extendedHeaderSize);
+		}
+
 		return formatter.toString();
 	}
 }