Add smear checks and missing absolute flag to walk_internal_list

Author: atcuno

volatility3/framework/symbols/linux/__init__.py

@@ -430,13 +430,36 @@ def lookup_module_address(
 
     @classmethod
     def walk_internal_list(cls, vmlinux, struct_name, list_member, list_start):
+        count = 0
+        seen = set()
+
         while list_start:
+            if list_start.vol.offset in seen:
+                vollog.debug(
+                    "walk_internal_list: Repeat entry found. Stopping enumeration"
+                )
+                break
+            seen.add(list_start.vol.offset)
+
+            if not (list_start and list_start.is_readable()):
+                break
+
             list_struct = vmlinux.object(
-                object_type=struct_name, offset=list_start.vol.offset
+                object_type=struct_name, offset=list_start.vol.offset, absolute=True
             )
+
             yield list_struct
+
             list_start = getattr(list_struct, list_member)
 
+            if count == 4096:
+                vollog.debug(
+                    f"walk_internal_list: Breaking list enumeration at {count}"
+                )
+                break
+
+            count += 1
+
     @classmethod
     def container_of(
         cls,