- Implemented a safe multiply function safe_multiply_offer in the Afloat pallet. This function checks for possible arithmetic overflow when multiplying two balances - a critical action in the process of starting a sell order. Ensuring the safety of this operation will increase the reliability and robustness of our pallet.

- Added the `ArithmeticOverflow` error to the Afloat pallet error definitions. This error is used within the implementation of the safe multiplication function to catch the scenario of multiplication operations exceeding the maximum balance limit.
- Updated the `replicate_overflow_for_start_take_sell_order` test case in the Afloat pallet to confirm the correct operation of the `safe_multiply_offer` function and the proper detection of arithmetic overflows. It ensures that when a multiplication operation would result in an overflow, the `ArithmeticOverflow` error is correctly returned.

Author: didiermis

pallets/afloat/src/functions.rs

@@ -4,16 +4,16 @@ use frame_support::pallet_prelude::*;
 use frame_system::{pallet_prelude::*, RawOrigin};
 use pallet_fruniques::types::{Attributes, CollectionDescription, FruniqueRole, ParentInfo};
 use pallet_gated_marketplace::types::{Marketplace, MarketplaceRole};
-use sp_runtime::{traits::StaticLookup, Permill};
 // use frame_support::traits::OriginTrait;
 use core::convert::TryInto;
 use frame_support::traits::Time;
 use pallet_rbac::types::{IdOrVec, RoleBasedAccessControl, RoleId};
 use scale_info::prelude::vec;
 use sp_io::hashing::blake2_256;
 use sp_runtime::{
+	Permill,
 	sp_std::{str, vec::Vec},
-	traits::Zero,
+	traits::{Zero, StaticLookup, CheckedMul},
 };
 
 impl<T: Config> Pallet<T> {
@@ -473,6 +473,9 @@ impl<T: Config> Pallet<T> {
 			offer.tax_credit_amount_remaining >= tax_credit_amount,
 			Error::<T>::NotEnoughTaxCreditsAvailable
 		);
+
+		// check arithmatic overflow
+		Self::safe_multiply_offer(offer.price_per_credit, tax_credit_amount)?;
 		//ensure user has enough afloat balance
 		ensure!(
 			Self::do_get_afloat_balance(who.clone())? >=
@@ -935,6 +938,14 @@ impl<T: Config> Pallet<T> {
 			})
 	}
 
+	fn safe_multiply_offer(
+		factor1: T::Balance,
+		factor2: T::Balance
+	) -> DispatchResult {
+		factor1.checked_mul(&factor2).ok_or_else(|| Error::<T>::ArithmeticOverflow)?;
+		Ok(())
+	}
+
 	fn get_all_roles_for_user(account_id: T::AccountId) -> Result<Vec<AfloatRole>, DispatchError> {
 		let roles_storage = <T as pallet::Config>::Rbac::get_roles_by_user(
 			account_id.clone(),

pallets/afloat/src/lib.rs

@@ -146,6 +146,8 @@ pub mod pallet {
 		ChildOfferIdNotFound,
 		// Tax credit amount underflow
 		Underflow,
+		// Arithmetic multiplication overflow
+		ArithmeticOverflow,
 		// Afloat marketplace label too long
 		LabelTooLong,
 		// Afloat asset has not been set

pallets/afloat/src/tests.rs

@@ -60,11 +60,14 @@ fn replicate_overflow_for_start_take_sell_order() {
 		));
 
 		let (offer_id, offer) = AfloatOffers::<Test>::iter().next().unwrap().clone();
-		assert_ok!(Afloat::start_take_sell_order(
-			RawOrigin::Signed(other_user.clone()).into(),
-			offer_id,
-			10
-		));
+		assert_noop!(
+			Afloat::start_take_sell_order(
+				RawOrigin::Signed(other_user.clone()).into(),
+				offer_id,
+				10
+			),
+			Error::<Test>::ArithmeticOverflow
+		);
 	});
 }