From 21a935010a80d13642516790f36cfe33e14a4099 Mon Sep 17 00:00:00 2001
From: Matthias <matthias_de@gmx.net>
Date: Sun, 16 Jul 2023 12:12:34 +0200
Subject: [PATCH] Fixed a problem when a journal bud is not mapped Fixed a
 problem when a corrupted inode with invalid ino_size field (e.g. ludicrously
 huge size) is being dumped Fixed a problem caused when decompressing data
 fails

---
 .gitignore                     |  7 ++-----
 ubift/cli/renderer.py          |  2 +-
 ubift/framework/compression.py | 29 +++++++++++++++++++----------
 ubift/framework/ubifs.py       |  3 +++
 4 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/.gitignore b/.gitignore
index c2948b1..d7c8fd3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -231,8 +231,5 @@ fabric.properties
 # libreoffice files
 **/.~lock*
 
-# ocrmypdf docker container
-data/ocrmypdf.tar
-
-# protege tempfiles
-data/catalog-v001.xml
\ No newline at end of file
+# local files
+/utils/
diff --git a/ubift/cli/renderer.py b/ubift/cli/renderer.py
index 838c592..54e6401 100644
--- a/ubift/cli/renderer.py
+++ b/ubift/cli/renderer.py
@@ -364,7 +364,7 @@ def write_to_file(inode: UBIFS_INO_NODE, data_nodes: List[UBIFS_DATA_NODE], abs_
 
             accu_size += len(data_node.decompressed_data)
 
-        if inode.ino_size > accu_size:
+        if inode.ino_size > accu_size and accu_size > 0:
             ubiftlog.warning(
                 f"[!] Size from inode field 'size' ({inode.ino_size}) is more than written bytes {accu_size}. Filling bytes with zeroes.")
             f.seek(inode.ino_size)
diff --git a/ubift/framework/compression.py b/ubift/framework/compression.py
index 486c89f..a29a4c5 100644
--- a/ubift/framework/compression.py
+++ b/ubift/framework/compression.py
@@ -5,6 +5,9 @@
 import lzo
 
 from ubift import exception
+from ubift.framework.structs.ubifs_structs import UBIFS_COMPRESSION_TYPE
+from ubift.logging import ubiftlog
+
 
 def decompress(data: bytes, compr_type: int, size: int = None) -> bytes:
     """
@@ -14,13 +17,19 @@ def decompress(data: bytes, compr_type: int, size: int = None) -> bytes:
     :param size: Size of buffer length that will fit output, needed by LZO-compression, for other compression methods this value does not matter. Value for this can be found in UBIFS_DATA_NODE
     :return: Uncompressed data
     """
-    if compr_type == 0: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_NONE
-        return data
-    elif compr_type == 1: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_LZO
-        return lzo.decompress(data, False, size)
-    elif compr_type == 2: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_ZLIB
-        return zlib.decompress(data, -zlib.MAX_WBITS)
-    elif compr_type == 3: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_ZSTD
-        return zstandard.decompress(data, size)
-    else:
-        raise exception.UBIFTException(f"Data is compressed with unknown type. ({compr_type})")
+    try:
+        if compr_type == 0: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_NONE
+            return data
+        elif compr_type == 1: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_LZO
+            return lzo.decompress(data, False, size)
+        elif compr_type == 2: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_ZLIB
+            return zlib.decompress(data, -zlib.MAX_WBITS)
+        elif compr_type == 3: # UBIFS_COMPRESSION_TYPE.UBIFS_COMPR_ZSTD
+            return zstandard.decompress(data, size)
+        else:
+            raise exception.UBIFTException(f"Data is compressed with unknown type. ({compr_type})")
+    except Exception as e:
+        ubiftlog.warn(
+            f"[-] Error while decompressing data using {UBIFS_COMPRESSION_TYPE(compr_type).name}: {e}")
+        return bytes()
+
diff --git a/ubift/framework/ubifs.py b/ubift/framework/ubifs.py
index ae8a20d..74c08c6 100644
--- a/ubift/framework/ubifs.py
+++ b/ubift/framework/ubifs.py
@@ -66,6 +66,9 @@ def _parse_bud(self, jhead: int) -> list:
         ubiftlog.info(f"[!] Parsing bud {UBIFS_JOURNAL_HEADS(jhead)}")
 
         ref_node = self._jheads[jhead]
+        if ref_node.lnum not in self._ubifs.ubi_volume.lebs:
+            ubiftlog.info(f"[-] Cannot parse bud {UBIFS_JOURNAL_HEADS(jhead)} because referenced LEB {ref_node.lnum} is not mapped.")
+            return []
         leb = self._ubifs.ubi_volume.lebs[ref_node.lnum]
         leb_offs = ref_node.offs