Prevent unhandled filesystem exceptions in modify_record (#737)

---------

Co-authored-by: Erik Schamper <[email protected]>

dissect/target/helpers/record_modifier.py

@@ -4,7 +4,7 @@
 from flow.record import GroupedRecord, Record, RecordDescriptor, fieldtypes
 
 from dissect.target import Target
-from dissect.target.exceptions import FilesystemError
+from dissect.target.exceptions import FileNotFoundError, FilesystemError
 from dissect.target.helpers.fsutil import TargetPath
 from dissect.target.helpers.hashutil import common
 from dissect.target.helpers.utils import StrEnum
@@ -44,7 +44,20 @@ def _resolve_path_records(field_name: str, resolved_path: TargetPath) -> Record:
 
 
 def _hash_path_records(field_name: str, resolved_path: TargetPath) -> Record:
-    """Hash files from path fields inside the record."""
+    """Hash files from path fields inside the record.
+
+    Args:
+        field_name: Name of the field.
+        resolved_path: Path to the file we should hash.
+
+    Raises:
+        FileNotFoundError: Raised if the provided ``resolved_path`` does not exist or is not a file on the target.
+
+    Returns: Modified record with digests of path field types.
+    """
+
+    if not resolved_path.exists() or not resolved_path.is_file():
+        raise FileNotFoundError(f"Path not found or is not a file: '{resolved_path}'")
 
     with resolved_path.open() as fh:
         path_hash = common(fh)
@@ -81,8 +94,14 @@ def modify_record(target: Target, record: Record, modifier_function: ModifierFun
     for field_name, resolved_path in _resolve_path_types(target, record):
         try:
             _record = modifier_function(field_name, resolved_path)
-        except FilesystemError:
-            pass
+        except FilesystemError as e:
+            target.log.warning(
+                "Unable to modify record '%s' with function '%s': %s",
+                record._desc.name,
+                modifier_function.__name__,
+                e,
+            )
+            target.log.debug("", exc_info=e)
         else:
             additional_records.append(_record)
 

tests/helpers/test_modifier.py

@@ -50,6 +50,8 @@ def test_hash_path_records_with_paths(
 
     with (
         patch.object(TargetPath, "open", mock_open(read_data=b"")),
+        patch("dissect.target.helpers.fsutil.TargetPath.exists", return_value=True),
+        patch("dissect.target.helpers.fsutil.TargetPath.is_file", return_value=True),
         patch("dissect.target.helpers.record_modifier.common", return_value=HASHES),
     ):
         hashed_record = hash_function(target_win, record)