From 8bd01d8cf868fff8630eeebca6db3c8f8d35aff0 Mon Sep 17 00:00:00 2001
From: Dev Ojha <ValarDragon@users.noreply.github.com>
Date: Wed, 9 Nov 2022 15:27:57 -0800
Subject: [PATCH] Add keeper level panic catches (#3312)

* Add keeper level panic catches

* Add changelog

* Add panic catch for swap

(cherry picked from commit f88577d30e35f3bc0ee7ddc79a727818fc1b50cb)
---
 CHANGELOG.md                  |  1 +
 x/gamm/keeper/pool_service.go | 28 ++++++++++++++++++++++++++--
 x/gamm/keeper/swap.go         | 15 +++++++++++++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c7c9739d788..0da28fc90b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -54,6 +54,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * [#2914](https://github.com/osmosis-labs/osmosis/pull/2914) Remove out of gas panics from node logs
 * [#2937](https://github.com/osmosis-labs/osmosis/pull/2937) End block ordering - staking after gov and module sorting.
 * [#2923](https://github.com/osmosis-labs/osmosis/pull/2923) TWAP calculation now errors if it uses records that have errored previously.
+* [#3312](https://github.com/osmosis-labs/osmosis/pull/3312) Add better panic catches within GAMM txs
 
 ### Misc Improvements
 
diff --git a/x/gamm/keeper/pool_service.go b/x/gamm/keeper/pool_service.go
index 0f630e10a7e..b464dc952c6 100644
--- a/x/gamm/keeper/pool_service.go
+++ b/x/gamm/keeper/pool_service.go
@@ -202,6 +202,14 @@ func (k Keeper) JoinPoolNoSwap(
 	shareOutAmount sdk.Int,
 	tokenInMaxs sdk.Coins,
 ) (tokenIn sdk.Coins, sharesOut sdk.Int, err error) {
+	// defer to catch panics, in case something internal overflows.
+	defer func() {
+		if r := recover(); r != nil {
+			tokenIn = sdk.Coins{}
+			sharesOut = sdk.Int{}
+			err = fmt.Errorf("function JoinPoolNoSwap failed due to internal reason: %v", r)
+		}
+	}()
 	// all pools handled within this method are pointer references, `JoinPool` directly updates the pools
 	pool, err := k.GetPoolAndPoke(ctx, poolId)
 	if err != nil {
@@ -281,13 +289,21 @@ func (k Keeper) JoinSwapExactAmountIn(
 	poolId uint64,
 	tokensIn sdk.Coins,
 	shareOutMinAmount sdk.Int,
-) (sdk.Int, error) {
+) (sharesOut sdk.Int, err error) {
+	// defer to catch panics, in case something internal overflows.
+	defer func() {
+		if r := recover(); r != nil {
+			sharesOut = sdk.Int{}
+			err = fmt.Errorf("function JoinSwapExactAmountIn failed due to internal reason: %v", r)
+		}
+	}()
+
 	pool, err := k.getPoolForSwap(ctx, poolId)
 	if err != nil {
 		return sdk.Int{}, err
 	}
 
-	sharesOut, err := pool.JoinPool(ctx, tokensIn, pool.GetSwapFee(ctx))
+	sharesOut, err = pool.JoinPool(ctx, tokensIn, pool.GetSwapFee(ctx))
 	switch {
 	case err != nil:
 		return sdk.ZeroInt(), err
@@ -318,6 +334,14 @@ func (k Keeper) JoinSwapShareAmountOut(
 	shareOutAmount sdk.Int,
 	tokenInMaxAmount sdk.Int,
 ) (tokenInAmount sdk.Int, err error) {
+	// defer to catch panics, in case something internal overflows.
+	defer func() {
+		if r := recover(); r != nil {
+			tokenInAmount = sdk.Int{}
+			err = fmt.Errorf("function JoinSwapShareAmountOut failed due to internal reason: %v", r)
+		}
+	}()
+
 	pool, err := k.getPoolForSwap(ctx, poolId)
 	if err != nil {
 		return sdk.Int{}, err
diff --git a/x/gamm/keeper/swap.go b/x/gamm/keeper/swap.go
index f048784c269..e8486a4a4f0 100644
--- a/x/gamm/keeper/swap.go
+++ b/x/gamm/keeper/swap.go
@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"errors"
+	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
@@ -50,6 +51,13 @@ func (k Keeper) swapExactAmountIn(
 	}
 	tokensIn := sdk.Coins{tokenIn}
 
+	defer func() {
+		if r := recover(); r != nil {
+			tokenOutAmount = sdk.Int{}
+			err = fmt.Errorf("function swapExactAmountIn failed due to internal reason: %v", r)
+		}
+	}()
+
 	// Executes the swap in the pool and stores the output. Updates pool assets but
 	// does not actually transfer any tokens to or from the pool.
 	tokenOutCoin, err := pool.SwapOutAmtGivenIn(ctx, tokensIn, tokenOutDenom, swapFee)
@@ -109,6 +117,13 @@ func (k Keeper) swapExactAmountOut(
 		return sdk.Int{}, errors.New("cannot trade same denomination in and out")
 	}
 
+	defer func() {
+		if r := recover(); r != nil {
+			tokenInAmount = sdk.Int{}
+			err = fmt.Errorf("function swapExactAmountOut failed due to internal reason: %v", r)
+		}
+	}()
+
 	poolOutBal := pool.GetTotalPoolLiquidity(ctx).AmountOf(tokenOut.Denom)
 	if tokenOut.Amount.GTE(poolOutBal) {
 		return sdk.Int{}, sdkerrors.Wrapf(types.ErrTooManyTokensOut,