diff --git a/substrate/frame/staking/src/lib.rs b/substrate/frame/staking/src/lib.rs index 3fda830650..af326e27c6 100644 --- a/substrate/frame/staking/src/lib.rs +++ b/substrate/frame/staking/src/lib.rs @@ -1474,11 +1474,13 @@ decl_module! { let mut ledger = Self::ledger(&controller).ok_or(Error::::NotController)?; let stash_balance = T::Currency::free_balance(&stash); - if let Some(extra) = stash_balance.checked_sub(&ledger.total) { let extra = extra.min(max_additional); ledger.total += extra; ledger.active += extra; + // last check: the new active amount of ledger must be more than ED. + ensure!(ledger.active >= T::Currency::minimum_balance(), Error::::InsufficientValue); + Self::deposit_event(RawEvent::Bonded(stash, extra)); Self::update_ledger(&controller, &ledger); } @@ -1586,7 +1588,7 @@ decl_module! { ledger = ledger.consolidate_unlocked(current_era) } - let post_info_weight = if ledger.unlocking.is_empty() && ledger.active.is_zero() { + let post_info_weight = if ledger.unlocking.is_empty() && ledger.active <= T::Currency::minimum_balance() { // This account must have called `unbond()` with some value that caused the active // portion to fall below existential deposit + will have no more unlocking chunks // left. We can now safely remove all staking-related information. @@ -1973,6 +1975,9 @@ decl_module! { ensure!(!ledger.unlocking.is_empty(), Error::::NoUnlockChunk); let ledger = ledger.rebond(value); + // last check: the new active amount of ledger must be more than ED. + ensure!(ledger.active >= T::Currency::minimum_balance(), Error::::InsufficientValue); + Self::update_ledger(&controller, &ledger); Ok(Some( 35 * WEIGHT_PER_MICROS diff --git a/substrate/frame/staking/src/mock.rs b/substrate/frame/staking/src/mock.rs index 5deae116e5..76689503f6 100644 --- a/substrate/frame/staking/src/mock.rs +++ b/substrate/frame/staking/src/mock.rs @@ -579,8 +579,18 @@ fn assert_is_stash(acc: AccountId) { fn assert_ledger_consistent(ctrl: AccountId) { // ensures ledger.total == ledger.active + sum(ledger.unlocking). let ledger = Staking::ledger(ctrl).expect("Not a controller."); - let real_total: Balance = ledger.unlocking.iter().fold(ledger.active, |a, c| a + c.value); + let real_total: Balance = ledger + .unlocking + .iter() + .fold(ledger.active, |a, c| a + c.value); assert_eq!(real_total, ledger.total); + assert!( + ledger.active >= Balances::minimum_balance() || ledger.active == 0, + "{}: active ledger amount ({}) must be greater than ED {}", + ctrl, + ledger.active, + Balances::minimum_balance() + ); } pub(crate) fn bond_validator(stash: AccountId, ctrl: AccountId, val: Balance) { diff --git a/substrate/frame/staking/src/tests.rs b/substrate/frame/staking/src/tests.rs index c50964a33b..79edc012cd 100644 --- a/substrate/frame/staking/src/tests.rs +++ b/substrate/frame/staking/src/tests.rs @@ -4696,3 +4696,85 @@ fn payout_to_any_account_works() { assert!(Balances::free_balance(42) > 0); }) } + +#[test] +fn cannot_bond_extra_to_lower_than_ed() { + ExtBuilder::default() + .existential_deposit(10) + .build_and_execute(|| { + // stash must have more balance than bonded for this to work. + assert_eq!(Balances::free_balance(&21), 512_000); + + // initial stuff. + assert_eq!( + Staking::ledger(&20).unwrap(), + StakingLedger { + stash: 21, + total: 1000, + active: 1000, + unlocking: vec![], + claimed_rewards: vec![] + } + ); + + // unbond all of it. + assert_ok!(Staking::unbond(Origin::signed(20), 1000)); + assert_eq!( + Staking::ledger(&20).unwrap(), + StakingLedger { + stash: 21, + total: 1000, + active: 0, + unlocking: vec![UnlockChunk { value: 1000, era: 3 }], + claimed_rewards: vec![] + } + ); + + // now bond a wee bit more + assert_noop!( + Staking::bond_extra(Origin::signed(21), 5), + Error::::InsufficientValue, + ); + }) +} + +#[test] +fn cannot_rebond_to_lower_than_ed() { + ExtBuilder::default() + .existential_deposit(10) + .build_and_execute(|| { + // stash must have more balance than bonded for this to work. + assert_eq!(Balances::free_balance(&21), 512_000); + + // initial stuff. + assert_eq!( + Staking::ledger(&20).unwrap(), + StakingLedger { + stash: 21, + total: 1000, + active: 1000, + unlocking: vec![], + claimed_rewards: vec![] + } + ); + + // unbond all of it. + assert_ok!(Staking::unbond(Origin::signed(20), 1000)); + assert_eq!( + Staking::ledger(&20).unwrap(), + StakingLedger { + stash: 21, + total: 1000, + active: 0, + unlocking: vec![UnlockChunk { value: 1000, era: 3 }], + claimed_rewards: vec![] + } + ); + + // now bond a wee bit more + assert_noop!( + Staking::rebond(Origin::signed(20), 5), + Error::::InsufficientValue, + ); + }) +}