Core: Fix up github security issues

This fixes an unused import, an improper use of self and lots and lots
of places where we implicitly return None.  This now explicitly returns
None to improve readability and prevent mixed implicit and explicit
return values.  This should also somewhat aid type checking by humans.

Author: ikelos

volatility3/cli/__init__.py

@@ -662,7 +662,7 @@ def __init__(self, filename: str):
             def close(self):
                 # Don't overcommit
                 if self.closed:
-                    return
+                    return None
 
                 self.seek(0)
 
@@ -712,7 +712,7 @@ def close(self):
                 """Closes and commits the file (by moving the temporary file to the correct name"""
                 # Don't overcommit
                 if self._file.closed:
-                    return
+                    return None
 
                 self._file.close()
                 output_filename = self._get_final_filename()

volatility3/cli/volshell/generic.py

@@ -108,7 +108,7 @@ def help(self, *args):
         """Describes the available commands"""
         if args:
             help(*args)
-            return
+            return None
 
         variables = []
         print("\nMethods:")
@@ -325,7 +325,7 @@ def display_type(
             (str, interfaces.objects.ObjectInterface, interfaces.objects.Template),
         ):
             print("Cannot display information about non-type object")
-            return
+            return None
 
         if not isinstance(object, str):
             # Mypy requires us to order things this way
@@ -453,7 +453,7 @@ def display_symbols(self, symbol_table: str = None):
         """Prints an alphabetical list of symbols for a symbol table"""
         if symbol_table is None:
             print("No symbol table provided")
-            return
+            return None
         longest_offset = longest_name = 0
 
         table = self.context.symbol_space[symbol_table]

volatility3/cli/volshell/linux.py

@@ -35,9 +35,9 @@ def change_task(self, pid=None):
                 process_layer = task.add_process_layer()
                 if process_layer is not None:
                     self.change_layer(process_layer)
-                    return
+                    return None
                 print(f"Layer for task ID {pid} could not be constructed")
-                return
+                return None
         print(f"No task with task ID {pid} found")
 
     def list_tasks(self):

volatility3/cli/volshell/mac.py

@@ -35,9 +35,9 @@ def change_task(self, pid=None):
                 process_layer = task.add_process_layer()
                 if process_layer is not None:
                     self.change_layer(process_layer)
-                    return
+                    return None
                 print(f"Layer for task ID {pid} could not be constructed")
-                return
+                return None
         print(f"No task with task ID {pid} found")
 
     def list_tasks(self, method=None):

volatility3/cli/volshell/windows.py

@@ -32,7 +32,7 @@ def change_process(self, pid=None):
             if process.UniqueProcessId == pid:
                 process_layer = process.add_process_layer()
                 self.change_layer(process_layer)
-                return
+                return None
         print(f"No process with process ID {pid} found")
 
     def list_processes(self):

volatility3/framework/automagic/module.py

@@ -29,9 +29,9 @@ def __call__(
                     requirement.requirements[req],
                     progress_callback,
                 )
-            return
+            return None
         if not requirement.unsatisfied(context, config_path):
-            return
+            return None
         # The requirement is unfulfilled and is a ModuleRequirement
 
         context.config[
@@ -43,7 +43,7 @@ def __call__(
                 requirement.requirements[req].unsatisfied(context, new_config_path)
                 and req != "offset"
             ):
-                return
+                return None
 
         # We now just have the offset requirement, but the layer requirement has been fulfilled.
         # Unfortunately we don't know the layer name requirement's exact name

volatility3/framework/automagic/stacker.py

@@ -103,7 +103,7 @@ def stack(
                 appropriate_config_path, layer_name = result
                 context.config.merge(appropriate_config_path, subconfig)
                 context.config[appropriate_config_path] = top_layer_name
-                return
+                return None
             self._cached = None
 
         new_context = context.clone()

volatility3/framework/automagic/symbol_finder.py

@@ -69,7 +69,7 @@ def __call__(
 
         # Bomb out early if our details haven't been configured
         if self.symbol_class is None:
-            return
+            return None
 
         self._requirements = self.find_requirements(
             context,
@@ -120,7 +120,7 @@ def _banner_scan(
 
         # Bomb out early if there's no banners
         if not self.banners:
-            return
+            return None
 
         mss = scanners.MultiStringScanner([x for x in self.banners if x is not None])
 

volatility3/framework/layers/intel.py

@@ -331,9 +331,9 @@ def _mapping(
             except exceptions.InvalidAddressException:
                 if not ignore_errors:
                     raise
-                return
+                return None
             yield offset, length, mapped_offset, length, layer_name
-            return
+            return None
         while length > 0:
             try:
                 chunk_offset, page_size, layer_name = self._translate(offset)

volatility3/framework/layers/msf.py

@@ -47,7 +47,7 @@ def pdb_symbol_table(self) -> str:
     def read_streams(self):
         # Shortcut in case they've already been read
         if self._streams:
-            return
+            return None
 
         # Recover the root table, by recovering the root table index table...
         module = self.context.module(self.pdb_symbol_table, self._base_layer, offset=0)