Release crates io v1.7.0 staking backports (#3871)

Backports for 1.7: 
- #3639
- #3706

Relevant Issues:
- #3245

prdoc/pr_3639.prdoc

@@ -0,0 +1,19 @@
+title: Prevents staking controllers from becoming stashes of different ledgers; Ensures that no ledger in bad state is mutated.
+
+doc:
+  - audience: Runtime User
+    description: |
+      This PR introduces a fix to the staking logic which prevents an existing controller from bonding as a stash of another ledger, which
+      lead to staking ledger inconsistencies down the line. In addition, it adds a few (temporary) gates to prevent ledgers that are already
+      in a bad state from mutating its state.
+
+      In summary:
+      * Checks if stash is already a controller when calling `Call::bond` and fails if that's the case;
+      * Ensures that all fetching ledgers from storage are done through the `StakingLedger` API;
+      * Ensures that a `Error::BadState` is returned if the ledger bonding is in a bad state. This prevents bad ledgers from mutating (e.g.
+        `bond_extra`, `set_controller`, etc) its state and avoid further data inconsistencies.
+      * Prevents stashes which are controllers or another ledger from calling `set_controller`, since that may lead to a bad state.
+      * Adds further try-state runtime checks that check if there are ledgers in a bad state based on their bonded metadata.
+
+crates:
+- name: pallet-staking

prdoc/pr_3706.prdoc

@@ -0,0 +1,20 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Extrinsic to restore corrupted staking ledgers
+
+doc:
+  - audience: Runtime User
+    description: |
+      This PR adds a new extrinsic `Call::restore_ledger ` gated by `StakingAdmin` origin that restores a corrupted staking ledger. This extrinsic will be used to recover ledgers that were affected by the issue discussed in https://github.com/paritytech/polkadot-sdk/issues/3245.
+      The extrinsic will re-write the storage items associated with a stash account provided as input parameter. The data used to reset the ledger can be either i) fetched on-chain or ii) partially/totally set by the input parameters of the call.
+
+      Changes introduced:
+        - Adds `Call::restore_ledger ` extrinsic to recover a corrupted ledger;
+        - Adds trait `frame_support::traits::currency::InspectLockableCurrency` to allow external pallets to read current locks given an account and lock ID;
+        - Implements the `InspectLockableCurrency` in the pallet-balances.
+        - Adds staking locks try-runtime checks (https://github.com/paritytech/polkadot-sdk/issues/3751)
+
+crates: 
+ - name: pallet-staking
+ - name: pallet-balances

substrate/frame/balances/src/impl_currency.rs

@@ -28,8 +28,8 @@ use frame_support::{
 		tokens::{fungible, BalanceStatus as Status, Fortitude::Polite, Precision::BestEffort},
 		Currency, DefensiveSaturating, ExistenceRequirement,
 		ExistenceRequirement::AllowDeath,
-		Get, Imbalance, LockIdentifier, LockableCurrency, NamedReservableCurrency,
-		ReservableCurrency, SignedImbalance, TryDrop, WithdrawReasons,
+		Get, Imbalance, InspectLockableCurrency, LockIdentifier, LockableCurrency,
+		NamedReservableCurrency, ReservableCurrency, SignedImbalance, TryDrop, WithdrawReasons,
 	},
 };
 use frame_system::pallet_prelude::BlockNumberFor;
@@ -918,3 +918,12 @@ where
 		Self::update_locks(who, &locks[..]);
 	}
 }
+
+impl<T: Config<I>, I: 'static> InspectLockableCurrency<T::AccountId> for Pallet<T, I> {
+	fn balance_locked(id: LockIdentifier, who: &T::AccountId) -> Self::Balance {
+		Self::locks(who)
+			.into_iter()
+			.filter(|l| l.id == id)
+			.fold(Zero::zero(), |acc, l| acc + l.amount)
+	}
+}

substrate/frame/balances/src/tests/currency_tests.rs

@@ -24,8 +24,8 @@ use frame_support::{
 		BalanceStatus::{Free, Reserved},
 		Currency,
 		ExistenceRequirement::{self, AllowDeath, KeepAlive},
-		Hooks, LockIdentifier, LockableCurrency, NamedReservableCurrency, ReservableCurrency,
-		WithdrawReasons,
+		Hooks, InspectLockableCurrency, LockIdentifier, LockableCurrency, NamedReservableCurrency,
+		ReservableCurrency, WithdrawReasons,
 	},
 	StorageNoopGuard,
 };
@@ -88,6 +88,24 @@ fn basic_locking_should_work() {
 		});
 }
 
+#[test]
+fn inspect_lock_should_work() {
+	ExtBuilder::default()
+		.existential_deposit(1)
+		.monied(true)
+		.build_and_execute_with(|| {
+			Balances::set_lock(ID_1, &1, 10, WithdrawReasons::all());
+			Balances::set_lock(ID_2, &1, 10, WithdrawReasons::all());
+			Balances::set_lock(ID_1, &2, 20, WithdrawReasons::all());
+
+			assert_eq!(<Balances as InspectLockableCurrency<_>>::balance_locked(ID_1, &1), 10);
+			assert_eq!(<Balances as InspectLockableCurrency<_>>::balance_locked(ID_2, &1), 10);
+			assert_eq!(<Balances as InspectLockableCurrency<_>>::balance_locked(ID_1, &2), 20);
+			assert_eq!(<Balances as InspectLockableCurrency<_>>::balance_locked(ID_2, &2), 0);
+			assert_eq!(<Balances as InspectLockableCurrency<_>>::balance_locked(ID_1, &3), 0);
+		})
+}
+
 #[test]
 fn account_should_be_reaped() {
 	ExtBuilder::default()

substrate/frame/staking/Cargo.toml

@@ -38,10 +38,10 @@ frame-benchmarking = { path = "../benchmarking", default-features = false, optio
 rand_chacha = { version = "0.2", default-features = false, optional = true }
 
 [dev-dependencies]
+pallet-balances = { path = "../balances" }
 sp-tracing = { path = "../../primitives/tracing" }
 sp-core = { path = "../../primitives/core" }
 sp-npos-elections = { path = "../../primitives/npos-elections" }
-pallet-balances = { path = "../balances" }
 pallet-timestamp = { path = "../timestamp" }
 pallet-staking-reward-curve = { path = "reward-curve" }
 pallet-bags-list = { path = "../bags-list" }

substrate/frame/staking/src/benchmarking.rs

@@ -948,6 +948,15 @@ benchmarks! {
 		assert_eq!(MinCommission::<T>::get(), Perbill::from_percent(100));
 	}
 
+	restore_ledger {
+		let (stash, controller) = create_stash_controller::<T>(0, 100, RewardDestination::Staked)?;
+		// corrupt ledger.
+		Ledger::<T>::remove(controller);
+	}: _(RawOrigin::Root, stash.clone(), None, None, None)
+	verify {
+		assert_eq!(Staking::<T>::inspect_bond_state(&stash), Ok(LedgerIntegrityState::Ok));
+	}
+
 	impl_benchmark_test_suite!(
 		Staking,
 		crate::mock::ExtBuilder::default().has_stakers(true),

substrate/frame/staking/src/ledger.rs

@@ -32,8 +32,8 @@
 //! state consistency.
 
 use frame_support::{
-	defensive,
-	traits::{LockableCurrency, WithdrawReasons},
+	defensive, ensure,
+	traits::{Defensive, LockableCurrency, WithdrawReasons},
 };
 use sp_staking::StakingAccount;
 use sp_std::prelude::*;
@@ -106,18 +106,39 @@ impl<T: Config> StakingLedger<T> {
 	/// This getter can be called with either a controller or stash account, provided that the
 	/// account is properly wrapped in the respective [`StakingAccount`] variant. This is meant to
 	/// abstract the concept of controller/stash accounts from the caller.
+	///
+	/// Returns [`Error::BadState`] when a bond is in "bad state". A bond is in a bad state when a
+	/// stash has a controller which is bonding a ledger associated with another stash.
 	pub(crate) fn get(account: StakingAccount<T::AccountId>) -> Result<StakingLedger<T>, Error<T>> {
-		let controller = match account {
-			StakingAccount::Stash(stash) => <Bonded<T>>::get(stash).ok_or(Error::<T>::NotStash),
-			StakingAccount::Controller(controller) => Ok(controller),
-		}?;
+		let (stash, controller) = match account.clone() {
+			StakingAccount::Stash(stash) =>
+				(stash.clone(), <Bonded<T>>::get(&stash).ok_or(Error::<T>::NotStash)?),
+			StakingAccount::Controller(controller) => (
+				Ledger::<T>::get(&controller)
+					.map(|l| l.stash)
+					.ok_or(Error::<T>::NotController)?,
+				controller,
+			),
+		};
 
-		<Ledger<T>>::get(&controller)
+		let ledger = <Ledger<T>>::get(&controller)
 			.map(|mut ledger| {
 				ledger.controller = Some(controller.clone());
 				ledger
 			})
-			.ok_or(Error::<T>::NotController)
+			.ok_or(Error::<T>::NotController)?;
+
+		// if ledger bond is in a bad state, return error to prevent applying operations that may
+		// further spoil the ledger's state. A bond is in bad state when the bonded controller is
+		// associted with a different ledger (i.e. a ledger with a different stash).
+		//
+		// See <https://github.com/paritytech/polkadot-sdk/issues/3245> for more details.
+		ensure!(
+			Bonded::<T>::get(&stash) == Some(controller) && ledger.stash == stash,
+			Error::<T>::BadState
+		);
+
+		Ok(ledger)
 	}
 
 	/// Returns the reward destination of a staking ledger, stored in [`Payee`].
@@ -201,6 +222,30 @@ impl<T: Config> StakingLedger<T> {
 		}
 	}
 
+	/// Sets the ledger controller to its stash.
+	pub(crate) fn set_controller_to_stash(self) -> Result<(), Error<T>> {
+		let controller = self.controller.as_ref()
+            .defensive_proof("Ledger's controller field didn't exist. The controller should have been fetched using StakingLedger.")
+            .ok_or(Error::<T>::NotController)?;
+
+		ensure!(self.stash != *controller, Error::<T>::AlreadyPaired);
+
+		// check if the ledger's stash is a controller of another ledger.
+		if let Some(bonded_ledger) = Ledger::<T>::get(&self.stash) {
+			// there is a ledger bonded by the stash. In this case, the stash of the bonded ledger
+			// should be the same as the ledger's stash. Otherwise fail to prevent data
+			// inconsistencies. See <https://github.com/paritytech/polkadot-sdk/pull/3639> for more
+			// details.
+			ensure!(bonded_ledger.stash == self.stash, Error::<T>::BadState);
+		}
+
+		<Ledger<T>>::remove(&controller);
+		<Ledger<T>>::insert(&self.stash, &self);
+		<Bonded<T>>::insert(&self.stash, &self.stash);
+
+		Ok(())
+	}
+
 	/// Clears all data related to a staking ledger and its bond in both [`Ledger`] and [`Bonded`]
 	/// storage items and updates the stash staking lock.
 	pub(crate) fn kill(stash: &T::AccountId) -> Result<(), Error<T>> {

substrate/frame/staking/src/lib.rs

@@ -485,6 +485,20 @@ pub struct StakingLedger<T: Config> {
 	controller: Option<T::AccountId>,
 }
 
+/// State of a ledger with regards with its data and metadata integrity.
+#[derive(PartialEq, Debug)]
+enum LedgerIntegrityState {
+	/// Ledger, bond and corresponding staking lock is OK.
+	Ok,
+	/// Ledger and/or bond is corrupted. This means that the bond has a ledger with a different
+	/// stash than the bonded stash.
+	Corrupted,
+	/// Ledger was corrupted and it has been killed.
+	CorruptedKilled,
+	/// Ledger and bond are OK, however the ledger's stash lock is out of sync.
+	LockCorrupted,
+}
+
 impl<T: Config> StakingLedger<T> {
 	/// Remove entries from `unlocking` that are sufficiently old and reduce the
 	/// total by the sum of their balances.

substrate/frame/staking/src/mock.rs

@@ -25,8 +25,8 @@ use frame_election_provider_support::{
 use frame_support::{
 	assert_ok, derive_impl, ord_parameter_types, parameter_types,
 	traits::{
-		ConstU64, Currency, EitherOfDiverse, FindAuthor, Get, Hooks, Imbalance, OnUnbalanced,
-		OneSessionHandler,
+		ConstU64, Currency, EitherOfDiverse, FindAuthor, Get, Hooks, Imbalance, LockableCurrency,
+		OnUnbalanced, OneSessionHandler, WithdrawReasons,
 	},
 	weights::constants::RocksDbWeight,
 };
@@ -813,6 +813,88 @@ pub(crate) fn bond_controller_stash(controller: AccountId, stash: AccountId) ->
 	Ok(())
 }
 
+// simulates `set_controller` without corrupted ledger checks for testing purposes.
+pub(crate) fn set_controller_no_checks(stash: &AccountId) {
+	let controller = Bonded::<Test>::get(stash).expect("testing stash should be bonded");
+	let ledger = Ledger::<Test>::get(&controller).expect("testing ledger should exist");
+
+	Ledger::<Test>::remove(&controller);
+	Ledger::<Test>::insert(stash, ledger);
+	Bonded::<Test>::insert(stash, stash);
+}
+
+// simulates `bond_extra` without corrupted ledger checks for testing purposes.
+pub(crate) fn bond_extra_no_checks(stash: &AccountId, amount: Balance) {
+	let controller = Bonded::<Test>::get(stash).expect("bond must exist to bond_extra");
+	let mut ledger = Ledger::<Test>::get(&controller).expect("ledger must exist to bond_extra");
+
+	let new_total = ledger.total + amount;
+	Balances::set_lock(crate::STAKING_ID, stash, new_total, WithdrawReasons::all());
+	ledger.total = new_total;
+	ledger.active = new_total;
+	Ledger::<Test>::insert(controller, ledger);
+}
+
+pub(crate) fn setup_double_bonded_ledgers() {
+	let init_ledgers = Ledger::<Test>::iter().count();
+
+	let _ = Balances::make_free_balance_be(&333, 2000);
+	let _ = Balances::make_free_balance_be(&444, 2000);
+	let _ = Balances::make_free_balance_be(&555, 2000);
+	let _ = Balances::make_free_balance_be(&777, 2000);
+
+	assert_ok!(Staking::bond(RuntimeOrigin::signed(333), 10, RewardDestination::Staked));
+	assert_ok!(Staking::bond(RuntimeOrigin::signed(444), 20, RewardDestination::Staked));
+	assert_ok!(Staking::bond(RuntimeOrigin::signed(555), 20, RewardDestination::Staked));
+	// not relevant to the test case, but ensures try-runtime checks pass.
+	[333, 444, 555]
+		.iter()
+		.for_each(|s| Payee::<Test>::insert(s, RewardDestination::Staked));
+
+	// we want to test the case where a controller can also be a stash of another ledger.
+	// for that, we change the controller/stash bonding so that:
+	// * 444 becomes controller of 333.
+	// * 555 becomes controller of 444.
+	// * 777 becomes controller of 555.
+	let ledger_333 = Ledger::<Test>::get(333).unwrap();
+	let ledger_444 = Ledger::<Test>::get(444).unwrap();
+	let ledger_555 = Ledger::<Test>::get(555).unwrap();
+
+	// 777 becomes controller of 555.
+	Bonded::<Test>::mutate(555, |controller| *controller = Some(777));
+	Ledger::<Test>::insert(777, ledger_555);
+
+	// 555 becomes controller of 444.
+	Bonded::<Test>::mutate(444, |controller| *controller = Some(555));
+	Ledger::<Test>::insert(555, ledger_444);
+
+	// 444 becomes controller of 333.
+	Bonded::<Test>::mutate(333, |controller| *controller = Some(444));
+	Ledger::<Test>::insert(444, ledger_333);
+
+	// 333 is not controller anymore.
+	Ledger::<Test>::remove(333);
+
+	// checks. now we have:
+	// * +3 ledgers
+	assert_eq!(Ledger::<Test>::iter().count(), 3 + init_ledgers);
+
+	// * stash 333 has controller 444.
+	assert_eq!(Bonded::<Test>::get(333), Some(444));
+	assert_eq!(StakingLedger::<Test>::paired_account(StakingAccount::Stash(333)), Some(444));
+	assert_eq!(Ledger::<Test>::get(444).unwrap().stash, 333);
+
+	// * stash 444 has controller 555.
+	assert_eq!(Bonded::<Test>::get(444), Some(555));
+	assert_eq!(StakingLedger::<Test>::paired_account(StakingAccount::Stash(444)), Some(555));
+	assert_eq!(Ledger::<Test>::get(555).unwrap().stash, 444);
+
+	// * stash 555 has controller 777.
+	assert_eq!(Bonded::<Test>::get(555), Some(777));
+	assert_eq!(StakingLedger::<Test>::paired_account(StakingAccount::Stash(555)), Some(777));
+	assert_eq!(Ledger::<Test>::get(777).unwrap().stash, 555);
+}
+
 #[macro_export]
 macro_rules! assert_session_era {
 	($session:expr, $era:expr) => {