Merge pull request #4 from mangata-finance/fix/underflow

asset underflow fixed
gasp-xyz · Dec 8, 2020 · e5911f2 · e5911f2
2 parents c5e89e0 + 6761e74
commit e5911f2
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Showing 3 changed files with 22 additions and 10 deletions.
diff --git a/pallets/assets/src/lib.rs b/pallets/assets/src/lib.rs
@@ -247,6 +247,8 @@ decl_error! {
 		BalanceLow,
 		/// Balance should be non-zero
 		BalanceZero,
+		/// Overflow
+		Overflow,
 	}
 }
 
@@ -303,17 +305,21 @@ impl<T: Trait> Module<T> {
 		id
 	}
 
-	pub fn assets_mint(id: &T::AssetId, to: &T::AccountId, amount: &T::Balance) -> T::Balance {
+	pub fn assets_mint(id: &T::AssetId, to: &T::AccountId, amount: &T::Balance) -> DispatchResult {
+		let origin_balance = <Balances<T>>::get((id, to));
 		<Balances<T>>::mutate((id, to), |balance| *balance += *amount);
 		<TotalSupply<T>>::mutate((id), |total| *total += *amount);
-		<Balances<T>>::get((id, to))
+		let final_balance = <Balances<T>>::get((id, to));
+		ensure!(final_balance >= origin_balance, Error::<T>::Overflow);
+		Ok(())
 	}
 
-	pub fn assets_burn(id: &T::AssetId, to: &T::AccountId, amount: &T::Balance) -> T::Balance {
-		//TODO ensure amount
-		<Balances<T>>::mutate((id, to), |balance| *balance -= *amount);
+	pub fn assets_burn(id: &T::AssetId, from: &T::AccountId, amount: &T::Balance) -> DispatchResult {
+		let origin_balance = <Balances<T>>::get((id, from));
+		ensure!(origin_balance >= *amount, Error::<T>::BalanceLow);
+		<Balances<T>>::mutate((id, from), |balance| *balance -= *amount);
 		<TotalSupply<T>>::mutate((id), |total| *total -= *amount);
-		<Balances<T>>::get((id, to))
+		Ok(())
 	}
 }
 

diff --git a/pallets/erc20-app/src/lib.rs b/pallets/erc20-app/src/lib.rs
@@ -24,7 +24,7 @@ use sp_core::{H160, U256};
 use frame_system::{self as system, ensure_signed};
 use frame_support::{
 	decl_error, decl_event, decl_module, decl_storage,
-	dispatch::DispatchResult,
+	dispatch::DispatchResult, ensure,
 };
 
 use artemis_core::{Application, BridgedAssetId};
@@ -66,6 +66,8 @@ decl_error! {
 		InvalidAssetId,
 		/// The submitted payload could not be decoded.
 		InvalidPayload,
+		/// Asset could not be burned
+		BurnFailure,
 	}
 }
 
@@ -89,8 +91,9 @@ decl_module! {
 
 			// <asset::Module<T>>::do_burn(asset_id, &who, amount)?;
 			let native_asset_id = <asset::Module<T>>::get_native_asset_id(asset_id);
-			<assets::Module<T>>::assets_burn(&native_asset_id, &who, &amount.low_u128().saturated_into::<T::Balance>());
+			let result = <assets::Module<T>>::assets_burn(&native_asset_id, &who, &amount.low_u128().saturated_into::<T::Balance>());
 
+			ensure!(result.is_ok(), Error::<T>::BurnFailure);
 			Self::deposit_event(RawEvent::Transfer(asset_id, who.clone(), recipient, amount));
 			Ok(())
 		}

diff --git a/pallets/eth-app/src/lib.rs b/pallets/eth-app/src/lib.rs
@@ -21,7 +21,7 @@
 use frame_system::{self as system, ensure_signed};
 use frame_support::{
 	decl_error, decl_event, decl_module, decl_storage,
-	dispatch::DispatchResult,
+	dispatch::DispatchResult, ensure,
 };
 use sp_std::prelude::*;
 use sp_core::{H160, U256};
@@ -66,6 +66,8 @@ decl_error! {
 	pub enum Error for Module<T: Trait> {
 		/// The submitted payload could not be decoded.
 		InvalidPayload,
+		/// Asset could not be burned
+		BurnFailure,
 	}
 }
 
@@ -86,8 +88,9 @@ decl_module! {
 
 			// <asset::Module<T>>::do_burn(asset_id, &who, amount)?;
 			let asset_id = <asset::Module<T>>::get_native_asset_id(asset_id);
-			<assets::Module<T>>::assets_burn(&asset_id, &who, &amount.low_u128().saturated_into::<T::Balance>());
+			let result = <assets::Module<T>>::assets_burn(&asset_id, &who, &amount.low_u128().saturated_into::<T::Balance>());
 
+			ensure!(result.is_ok(), Error::<T>::BurnFailure);
 			Self::deposit_event(RawEvent::Transfer(who.clone(), recipient, amount));
 			Ok(())
 		}