Validate sort keys against fixed set of allowed values

Author: MarcialRosales

deps/rabbitmq_top/src/rabbit_top_util.erl

@@ -25,9 +25,34 @@ toplist(Key, Info) ->
 sort_by_param(ReqData, Default) ->
     case rabbit_mgmt_util:qs_val(<<"sort">>, ReqData) of
         undefined -> Default;
-        Bin       -> rabbit_data_coercion:to_atom(Bin)
+        Bin       -> known_sort_key(Bin, Default)
     end.
 
+%% Validate the sort key against known column names to prevent atom table
+%% exhaustion from arbitrary user-supplied sort parameters.
+known_sort_key(<<"reduction_delta">>,   _) -> reduction_delta;
+known_sort_key(<<"memory">>,            _) -> memory;
+known_sort_key(<<"message_queue_len">>, _) -> message_queue_len;
+known_sort_key(<<"reductions">>,        _) -> reductions;
+known_sort_key(<<"status">>,            _) -> status;
+known_sort_key(<<"buffer_len">>,        _) -> buffer_len;
+known_sort_key(<<"pid">>,               _) -> pid;
+%% ETS table sort keys
+known_sort_key(<<"size">>,                  _) -> size;
+known_sort_key(<<"name">>,                  _) -> name;
+known_sort_key(<<"owner">>,                 _) -> owner;
+known_sort_key(<<"owner_name">>,            _) -> owner_name;
+known_sort_key(<<"type">>,                  _) -> type;
+known_sort_key(<<"protection">>,            _) -> protection;
+known_sort_key(<<"node">>,                  _) -> node;
+known_sort_key(<<"keypos">>,                _) -> keypos;
+known_sort_key(<<"compressed">>,            _) -> compressed;
+known_sort_key(<<"named_table">>,           _) -> named_table;
+known_sort_key(<<"write_concurrency">>,     _) -> write_concurrency;
+known_sort_key(<<"read_concurrency">>,      _) -> read_concurrency;
+known_sort_key(<<"decentralized_counters">>, _) -> decentralized_counters;
+known_sort_key(<<_/binary>>,            Default) -> Default.
+
 sort_order_param(ReqData) ->
     case rabbit_mgmt_util:qs_val(<<"sort_reverse">>, ReqData) of
         <<"true">> -> asc;

deps/rabbitmq_top/test/rabbit_top_util_SUITE.erl

@@ -0,0 +1,106 @@
+%% This Source Code Form is subject to the terms of the Mozilla Public
+%% License, v. 2.0. If a copy of the MPL was not distributed with this
+%% file, You can obtain one at https://mozilla.org/MPL/2.0/.
+%%
+%% Copyright (c) 2007-2026 Broadcom. All Rights Reserved. The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries. All rights reserved.
+%%
+
+-module(rabbit_top_util_SUITE).
+
+-compile(export_all).
+
+-include_lib("common_test/include/ct.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+all() ->
+    [
+     {group, unit_tests}
+    ].
+
+groups() ->
+    [
+     {unit_tests, [parallel],
+      [
+       sort_by_param_known_process_keys,
+       sort_by_param_known_ets_table_keys,
+       sort_by_param_missing_uses_default,
+       sort_by_param_unknown_uses_default,
+       sort_by_param_unknown_does_not_create_atoms
+      ]}
+    ].
+
+init_per_suite(Config) ->
+    Config.
+
+end_per_suite(_Config) ->
+    ok.
+
+init_per_group(_, Config) ->
+    Config.
+
+end_per_group(_, _Config) ->
+    ok.
+
+init_per_testcase(_Testcase, Config) ->
+    Config.
+
+end_per_testcase(_Testcase, _Config) ->
+    ok.
+
+%%
+%% Tests
+%%
+
+sort_by_param_known_process_keys(_Config) ->
+    KnownKeys = [
+        {<<"reduction_delta">>,   reduction_delta},
+        {<<"memory">>,            memory},
+        {<<"message_queue_len">>, message_queue_len},
+        {<<"reductions">>,        reductions},
+        {<<"status">>,            status},
+        {<<"buffer_len">>,        buffer_len},
+        {<<"pid">>,               pid}
+    ],
+    [?assertEqual(Atom, rabbit_top_util:sort_by_param(req(Bin), some_default))
+     || {Bin, Atom} <- KnownKeys].
+
+sort_by_param_known_ets_table_keys(_Config) ->
+    KnownKeys = [
+        {<<"size">>,                  size},
+        {<<"name">>,                  name},
+        {<<"owner">>,                 owner},
+        {<<"owner_name">>,            owner_name},
+        {<<"type">>,                  type},
+        {<<"protection">>,            protection},
+        {<<"node">>,                  node},
+        {<<"keypos">>,                keypos},
+        {<<"compressed">>,            compressed},
+        {<<"named_table">>,           named_table},
+        {<<"write_concurrency">>,     write_concurrency},
+        {<<"read_concurrency">>,      read_concurrency},
+        {<<"decentralized_counters">>, decentralized_counters}
+    ],
+    [?assertEqual(Atom, rabbit_top_util:sort_by_param(req(Bin), some_default))
+     || {Bin, Atom} <- KnownKeys].
+
+sort_by_param_missing_uses_default(_Config) ->
+    ?assertEqual(my_default, rabbit_top_util:sort_by_param(#{qs => <<>>}, my_default)).
+
+sort_by_param_unknown_uses_default(_Config) ->
+    ?assertEqual(my_default, rabbit_top_util:sort_by_param(req(<<"unknown_column">>), my_default)).
+
+sort_by_param_unknown_does_not_create_atoms(_Config) ->
+    Key = <<"nonexistent_sort_key_for_rabbitmq_top_12345">>,
+    %% Confirm the atom does not exist before the call.
+    ?assertError(badarg, binary_to_existing_atom(Key, utf8)),
+    %% An unknown sort key must not create a new atom.
+    _ = rabbit_top_util:sort_by_param(req(Key), reduction_delta),
+    %% The atom must still not exist after the call.
+    ?assertError(badarg, binary_to_existing_atom(Key, utf8)).
+
+%%
+%% Helpers
+%%
+
+req(SortValue) ->
+    #{qs => <<"sort=", SortValue/binary>>}.