Make Multisig Pallet Bounded (#12457)

* Bounded multisig

* just use u32

Co-authored-by: parity-processbot <>

substrate/frame/multisig/src/lib.rs

@@ -51,7 +51,7 @@ pub mod migrations;
 mod tests;
 pub mod weights;
 
-use codec::{Decode, Encode};
+use codec::{Decode, Encode, MaxEncodedLen};
 use frame_support::{
 	dispatch::{
 		DispatchErrorWithPostInfo, DispatchResult, DispatchResultWithPostInfo, GetDispatchInfo,
@@ -60,7 +60,7 @@ use frame_support::{
 	ensure,
 	traits::{Currency, Get, ReservableCurrency},
 	weights::Weight,
-	RuntimeDebug,
+	BoundedVec, RuntimeDebug,
 };
 use frame_system::{self as system, RawOrigin};
 use scale_info::TypeInfo;
@@ -94,7 +94,9 @@ type BalanceOf<T> =
 /// A global extrinsic index, formed as the extrinsic index within a block, together with that
 /// block's height. This allows a transaction in which a multisig operation of a particular
 /// composite was created to be uniquely identified.
-#[derive(Copy, Clone, Eq, PartialEq, Encode, Decode, Default, RuntimeDebug, TypeInfo)]
+#[derive(
+	Copy, Clone, Eq, PartialEq, Encode, Decode, Default, RuntimeDebug, TypeInfo, MaxEncodedLen,
+)]
 pub struct Timepoint<BlockNumber> {
 	/// The height of the chain at the point in time.
 	height: BlockNumber,
@@ -103,8 +105,12 @@ pub struct Timepoint<BlockNumber> {
 }
 
 /// An open multisig operation.
-#[derive(Clone, Eq, PartialEq, Encode, Decode, Default, RuntimeDebug, TypeInfo)]
-pub struct Multisig<BlockNumber, Balance, AccountId> {
+#[derive(Clone, Eq, PartialEq, Encode, Decode, Default, RuntimeDebug, TypeInfo, MaxEncodedLen)]
+#[scale_info(skip_type_params(MaxApprovals))]
+pub struct Multisig<BlockNumber, Balance, AccountId, MaxApprovals>
+where
+	MaxApprovals: Get<u32>,
+{
 	/// The extrinsic when the multisig operation was opened.
 	when: Timepoint<BlockNumber>,
 	/// The amount held in reserve of the `depositor`, to be returned once the operation ends.
@@ -112,7 +118,7 @@ pub struct Multisig<BlockNumber, Balance, AccountId> {
 	/// The account who opened it (i.e. the first to approve it).
 	depositor: AccountId,
 	/// The approvals achieved so far, including the depositor. Always sorted.
-	approvals: Vec<AccountId>,
+	approvals: BoundedVec<AccountId, MaxApprovals>,
 }
 
 type CallHash = [u8; 32];
@@ -159,7 +165,7 @@ pub mod pallet {
 
 		/// The maximum amount of signatories allowed in the multisig.
 		#[pallet::constant]
-		type MaxSignatories: Get<u16>;
+		type MaxSignatories: Get<u32>;
 
 		/// Weight information for extrinsics in this pallet.
 		type WeightInfo: WeightInfo;
@@ -170,7 +176,6 @@ pub mod pallet {
 
 	#[pallet::pallet]
 	#[pallet::generate_store(pub(super) trait Store)]
-	#[pallet::without_storage_info]
 	#[pallet::storage_version(STORAGE_VERSION)]
 	pub struct Pallet<T>(_);
 
@@ -182,7 +187,7 @@ pub mod pallet {
 		T::AccountId,
 		Blake2_128Concat,
 		[u8; 32],
-		Multisig<T::BlockNumber, BalanceOf<T>, T::AccountId>,
+		Multisig<T::BlockNumber, BalanceOf<T>, T::AccountId, T::MaxSignatories>,
 	>;
 
 	#[pallet::error]
@@ -601,7 +606,9 @@ impl<T: Config> Pallet<T> {
 
 				if let Some(pos) = maybe_pos {
 					// Record approval.
-					m.approvals.insert(pos, who.clone());
+					m.approvals
+						.try_insert(pos, who.clone())
+						.map_err(|_| Error::<T>::TooManySignatories)?;
 					<Multisigs<T>>::insert(&id, call_hash, m);
 					Self::deposit_event(Event::MultisigApproval {
 						approving: who,
@@ -629,6 +636,9 @@ impl<T: Config> Pallet<T> {
 
 			T::Currency::reserve(&who, deposit)?;
 
+			let initial_approvals =
+				vec![who.clone()].try_into().map_err(|_| Error::<T>::TooManySignatories)?;
+
 			<Multisigs<T>>::insert(
 				&id,
 				call_hash,
@@ -636,7 +646,7 @@ impl<T: Config> Pallet<T> {
 					when: Self::timepoint(),
 					deposit,
 					depositor: who.clone(),
-					approvals: vec![who.clone()],
+					approvals: initial_approvals,
 				},
 			);
 			Self::deposit_event(Event::NewMultisig { approving: who, multisig: id, call_hash });