Validate Flashloan condition (#380)

* Validate Flashloan condition

Co-Authored-By: Henry-E <12613144+Henry-E@users.noreply.github.com>

* Add test

Co-Authored-By: Henry-E <12613144+Henry-E@users.noreply.github.com>

* Delete poc.patch

Co-Authored-By: Henry-E <12613144+Henry-E@users.noreply.github.com>

* Update flash_loan.rs

Co-Authored-By: Henry-E <12613144+Henry-E@users.noreply.github.com>

* Update flash_loan.rs

Co-Authored-By: Henry-E <12613144+Henry-E@users.noreply.github.com>

* restore original test

* clean up a little

---------

Co-authored-by: Henry-E <12613144+Henry-E@users.noreply.github.com>

Author: abdulrabbani00

programs/marginfi/src/instructions/marginfi_account/flashloan.rs

@@ -132,6 +132,11 @@ pub fn lending_account_end_flashloan<'info>(
 
     let mut marginfi_account = ctx.accounts.marginfi_account.load_mut()?;
 
+    check!(
+        !marginfi_account.get_flag(ACCOUNT_DISABLED),
+        MarginfiError::AccountDisabled
+    );
+
     marginfi_account.unset_flag(ACCOUNT_IN_FLASHLOAN);
 
     let (risk_result, _engine) =

programs/marginfi/src/instructions/marginfi_account/transfer_account.rs

@@ -1,9 +1,11 @@
 use crate::{
-    check_eq,
+    check, check_eq,
     constants::ACCOUNT_TRANSFER_FEE,
     events::{AccountEventHeader, MarginfiAccountTransferToNewAccount},
     prelude::*,
-    state::marginfi_account::{LendingAccount, MarginfiAccount, ACCOUNT_DISABLED},
+    state::marginfi_account::{
+        LendingAccount, MarginfiAccount, ACCOUNT_DISABLED, ACCOUNT_IN_FLASHLOAN,
+    },
 };
 use anchor_lang::prelude::*;
 use bytemuck::Zeroable;
@@ -20,6 +22,11 @@ pub fn transfer_to_new_account(ctx: Context<TransferToNewAccount>) -> MarginfiRe
 
     let mut old_account = ctx.accounts.old_marginfi_account.load_mut()?;
 
+    check!(
+        !old_account.get_flag(ACCOUNT_IN_FLASHLOAN),
+        MarginfiError::AccountInFlashloan
+    );
+
     // Prevent multiple migrations from the same account
     check_eq!(
         old_account.migrated_to,

programs/marginfi/tests/user_actions/flash_loan.rs

@@ -4,6 +4,8 @@ use fixtures::{assert_custom_error, prelude::*};
 use marginfi::prelude::*;
 use pretty_assertions::assert_eq;
 use solana_program_test::*;
+use solana_sdk::signature::Keypair;
+use solana_sdk::system_program;
 use solana_sdk::{
     compute_budget::ComputeBudgetInstruction, signer::Signer, transaction::Transaction,
 };
@@ -18,6 +20,7 @@ use solana_sdk::{
 // 7. Flashloan fails because of invalid `end_flashloan` ix order
 // 8. Flashloan fails because `end_flashloan` ix is for another account
 // 9. Flashloan fails because account is already in a flashloan
+// 10. Flashloan fails because account transfer during flashloan
 
 #[tokio::test]
 async fn flashloan_success_1op() -> anyhow::Result<()> {
@@ -41,7 +44,6 @@ async fn flashloan_success_1op() -> anyhow::Result<()> {
 
     let borrower_token_account_f_sol = test_f.sol_mint.create_empty_token_account().await;
     // Borrow SOL
-
     let borrow_ix = borrower_mfi_account_f
         .make_bank_borrow_ix(borrower_token_account_f_sol.key, sol_bank, 1_000)
         .await;
@@ -56,7 +58,7 @@ async fn flashloan_success_1op() -> anyhow::Result<()> {
         .await;
 
     let flash_loan_result = borrower_mfi_account_f
-        .try_flashloan(vec![borrow_ix, repay_ix], vec![], vec![])
+        .try_flashloan(vec![borrow_ix, repay_ix], vec![], vec![], None)
         .await;
 
     assert!(flash_loan_result.is_ok());
@@ -108,7 +110,7 @@ async fn flashloan_success_3op() -> anyhow::Result<()> {
     ixs.push(ComputeBudgetInstruction::set_compute_unit_limit(1_400_000));
 
     let flash_loan_result = borrower_mfi_account_f
-        .try_flashloan(ixs, vec![], vec![])
+        .try_flashloan(ixs, vec![], vec![], None)
         .await;
 
     assert!(flash_loan_result.is_ok());
@@ -137,13 +139,12 @@ async fn flashloan_fail_account_health() -> anyhow::Result<()> {
 
     let borrower_token_account_f_sol = test_f.sol_mint.create_empty_token_account().await;
     // Borrow SOL
-
     let borrow_ix = borrower_mfi_account_f
         .make_bank_borrow_ix(borrower_token_account_f_sol.key, sol_bank, 1_000)
         .await;
 
     let flash_loan_result = borrower_mfi_account_f
-        .try_flashloan(vec![borrow_ix], vec![], vec![sol_bank.key])
+        .try_flashloan(vec![borrow_ix], vec![], vec![sol_bank.key], None)
         .await;
 
     assert_custom_error!(
@@ -192,7 +193,7 @@ async fn flashloan_ok_missing_flag() -> anyhow::Result<()> {
         .await;
 
     let flash_loan_result = borrower_mfi_account_f
-        .try_flashloan(vec![borrow_ix, repay_ix], vec![], vec![])
+        .try_flashloan(vec![borrow_ix, repay_ix], vec![], vec![], None)
         .await;
 
     assert!(flash_loan_result.is_ok());
@@ -503,3 +504,66 @@ async fn flashloan_fail_already_in_flashloan() -> anyhow::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn flashloan_fail_account_transfer_during_flashloan() -> anyhow::Result<()> {
+    let test_f = TestFixture::new(Some(TestSettings::all_banks_payer_not_admin())).await;
+
+    let sol_bank = test_f.get_bank(&BankMint::Sol);
+
+    // Fund SOL lender
+    let lender_mfi_account_f = test_f.create_marginfi_account().await;
+    let lender_token_account_f_sol = test_f
+        .sol_mint
+        .create_token_account_and_mint_to(1_000)
+        .await;
+    lender_mfi_account_f
+        .try_bank_deposit(lender_token_account_f_sol.key, sol_bank, 1_000, None)
+        .await?;
+
+    // Fund SOL borrower
+    let borrower_mfi_account_f = test_f.create_marginfi_account().await;
+
+    let borrower_token_account_f_sol = test_f.sol_mint.create_empty_token_account().await;
+
+    // Borrow SOL
+    let borrow_ix = borrower_mfi_account_f
+        .make_bank_borrow_ix(borrower_token_account_f_sol.key, sol_bank, 1_000)
+        .await;
+
+    let new_authority = Keypair::new();
+    let new_account = Keypair::new();
+
+    let account = borrower_mfi_account_f.load().await;
+
+    let transfer_account_ix = Instruction {
+        program_id: marginfi::id(),
+        accounts: marginfi::accounts::TransferToNewAccount {
+            old_marginfi_account: borrower_mfi_account_f.key,
+            new_marginfi_account: new_account.pubkey(),
+            group: account.group,
+            authority: test_f.payer(),
+            new_authority: new_authority.pubkey(),
+            global_fee_wallet: test_f.marginfi_group.fee_wallet,
+            system_program: system_program::ID,
+        }
+        .to_account_metas(None),
+        data: marginfi::instruction::TransferToNewAccount {}.data(),
+    };
+
+    let flash_loan_result = borrower_mfi_account_f
+        .try_flashloan(
+            vec![borrow_ix, transfer_account_ix],
+            vec![],
+            vec![sol_bank.key],
+            Some(&new_account),
+        )
+        .await;
+
+    assert_custom_error!(
+        flash_loan_result.unwrap_err(),
+        MarginfiError::AccountInFlashloan
+    );
+
+    Ok(())
+}

test-utils/src/marginfi_account.rs

@@ -619,6 +619,7 @@ impl MarginfiAccountFixture {
         ixs: Vec<Instruction>,
         exclude_banks: Vec<Pubkey>,
         include_banks: Vec<Pubkey>,
+        signer: Option<&Keypair>,
     ) -> std::result::Result<(), BanksClientError> {
         let mut ixs = ixs;
         let start_ix = self
@@ -633,10 +634,16 @@ impl MarginfiAccountFixture {
 
         let ctx = self.ctx.borrow_mut();
 
+        let signers = if let Some(signer) = signer {
+            vec![&ctx.payer, signer]
+        } else {
+            vec![&ctx.payer]
+        };
+
         let tx = Transaction::new_signed_with_payer(
             &ixs,
             Some(&ctx.payer.pubkey().clone()),
-            &[&ctx.payer],
+            &signers,
             ctx.last_blockhash,
         );