diff --git a/volatility3/framework/symbols/linux/extensions/__init__.py b/volatility3/framework/symbols/linux/extensions/__init__.py index c9f7f50da..9b028acff 100644 --- a/volatility3/framework/symbols/linux/extensions/__init__.py +++ b/volatility3/framework/symbols/linux/extensions/__init__.py @@ -350,11 +350,21 @@ class maple_tree(objects.StructType): maple_tree_entry, parent, expected_maple_tree_depth, - seen=set(), + seen=None, current_depth=1, ): """Recursively parse Maple Tree Nodes and yield all non empty slots""" + # Create seen set if it does not exist, e.g. on the first call into this recursive function. This + # must be None or an existing set of addresses for MTEs that have already been processed or that + # should otherwise be ignored. If parsing from the root node for example this should be None on the + # first call. If you needed to parse all nodes downwards from part of the tree this should still be + # None. If however you wanted to parse from a node, but ignore some parts of the tree below it then + # this could be populated with the addresses of the nodes you wish to ignore. + + if seen == None: + seen = set() + # protect against unlikely loop if maple_tree_entry in seen: vollog.warning( @@ -363,6 +373,7 @@ class maple_tree(objects.StructType): return None else: seen.add(maple_tree_entry) + # check if we have exceeded the expected depth of this maple tree. # e.g. when current_depth is larger than expected_maple_tree_depth there may be an issue. # it is normal that expected_maple_tree_depth is equal to current_depth. @@ -371,6 +382,7 @@ class maple_tree(objects.StructType): f"The depth for the maple tree at {hex(self.vol.offset)} is {expected_maple_tree_depth}, however when parsing the nodes " f"a depth of {current_depth} was reached. This is unexpected and may lead to incorrect results." ) + # parse the mte to extract the pointer value, node type, and leaf status pointer = maple_tree_entry & ~(self.MAPLE_NODE_POINTER_MASK) node_type = (