fix(workers): avoid dynamic publisher atoms

changelog.d/publisher-worker-atoms.fix

@@ -0,0 +1 @@
+Avoid creating atoms from serialized PublisherWorker parameters.

lib/pleroma/workers/publisher_worker.ex

@@ -9,6 +9,13 @@ defmodule Pleroma.Workers.PublisherWorker do
 
   use Oban.Worker, queue: :federator_outgoing, max_attempts: 13
 
+  @publish_one_param_keys %{
+    "activity_id" => :activity_id,
+    "cc" => :cc,
+    "inbox" => :inbox,
+    "unreachable_since" => :unreachable_since
+  }
+
   @impl true
   def perform(%Job{args: %{"op" => "publish", "activity_id" => activity_id}}) do
     activity = Activity.get_by_id(activity_id)
@@ -16,7 +23,13 @@ defmodule Pleroma.Workers.PublisherWorker do
   end
 
   def perform(%Job{args: %{"op" => "publish_one", "params" => params}} = job) do
-    params = Map.new(params, fn {k, v} -> {String.to_atom(k), v} end)
+    params =
+      Enum.reduce(params, %{}, fn {key, value}, acc ->
+        case @publish_one_param_keys do
+          %{^key => atom_key} -> Map.put(acc, atom_key, value)
+          _ -> acc
+        end
+      end)
 
     # Cancel / skip the job if this server believed to be unreachable now
     if not Instances.reachable?(params.inbox) do

test/pleroma/workers/publisher_worker_test.exs

@@ -11,6 +11,7 @@ defmodule Pleroma.Workers.PublisherWorkerTest do
 
   alias Pleroma.Instances
   alias Pleroma.Object
+  alias Pleroma.Workers.PublisherWorker
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.CommonAPI
@@ -70,12 +71,12 @@ defmodule Pleroma.Workers.PublisherWorkerTest do
           max_attempts: 5
         }
 
-        assert {:error, :connection_error} = Pleroma.Workers.PublisherWorker.perform(job)
+        assert {:error, :connection_error} = PublisherWorker.perform(job)
         assert Instances.reachable?("https://example.com/inbox")
 
         # Final attempt
         job = %{job | attempt: 5}
-        assert {:error, :connection_error} = Pleroma.Workers.PublisherWorker.perform(job)
+        assert {:error, :connection_error} = PublisherWorker.perform(job)
         refute Instances.reachable?("https://example.com/inbox")
       end
     end
@@ -95,11 +96,36 @@ defmodule Pleroma.Workers.PublisherWorkerTest do
           max_attempts: 5
         }
 
-        assert :ok = Pleroma.Workers.PublisherWorker.perform(job)
+        assert :ok = PublisherWorker.perform(job)
         assert Instances.reachable?("https://example.com/inbox")
       end
     end
 
+    test "does not create atoms from unexpected job params", %{activity: activity} do
+      unknown_key = "unknown_#{System.unique_integer([:positive])}"
+
+      assert_raise ArgumentError, fn -> String.to_existing_atom(unknown_key) end
+
+      with_mock Pleroma.Web.Federator,
+        perform: fn :publish_one, _params -> {:ok, %{status: 200}} end do
+        job = %Oban.Job{
+          args: %{
+            "op" => "publish_one",
+            "params" => %{
+              "inbox" => "https://example.com/inbox",
+              "activity_id" => activity.id,
+              unknown_key => "ignored"
+            }
+          },
+          attempt: 1,
+          max_attempts: 5
+        }
+
+        assert :ok = PublisherWorker.perform(job)
+        assert_raise ArgumentError, fn -> String.to_existing_atom(unknown_key) end
+      end
+    end
+
     test "cancels job if server is unreachable", %{activity: activity} do
       # First mark the server as unreachable
       Instances.set_unreachable("https://example.com/inbox")
@@ -117,7 +143,7 @@ defmodule Pleroma.Workers.PublisherWorkerTest do
         max_attempts: 5
       }
 
-      assert {:cancel, :unreachable} = Pleroma.Workers.PublisherWorker.perform(job)
+      assert {:cancel, :unreachable} = PublisherWorker.perform(job)
     end
   end
 end