audit nits

Author: 0xripleys

token-lending/program/src/processor.rs

@@ -202,7 +202,6 @@ fn process_init_lending_market(
         token_program_id: *token_program_id.key,
         oracle_program_id: *oracle_program_id.key,
         switchboard_oracle_program_id: *switchboard_oracle_program_id.key,
-        current_slot: Clock::get()?.slot,
     });
     LendingMarket::pack(lending_market, &mut lending_market_info.data.borrow_mut())?;
 
@@ -793,7 +792,7 @@ fn _redeem_reserve_collateral<'a>(
             .rate_limiter
             .update(
                 clock.slot,
-                reserve.market_value(Decimal::from(liquidity_amount))?,
+                reserve.market_value_upper_bound(Decimal::from(liquidity_amount))?,
             )
             .map_err(|err| {
                 msg!("Market outflow limit exceeded! Please try again later.");
@@ -2071,7 +2070,7 @@ fn process_update_reserve_config(
         return Err(LendingError::InvalidMarketAuthority.into());
     }
 
-    // if window duration and max outflow are different, then create a new rate limiter instance.
+    // if window duration or max outflow are different, then create a new rate limiter instance.
     if rate_limiter_config != reserve.rate_limiter.config {
         reserve.rate_limiter = RateLimiter::new(rate_limiter_config, Clock::get()?.slot);
     }

token-lending/program/tests/two_prices.rs

@@ -270,6 +270,8 @@ async fn test_withdraw() {
 
     assert_eq!(balance_changes, expected_balance_changes);
 
+    test.advance_clock_by_slots(1).await;
+
     // we shouldn't be able to withdraw anything else
     for mint in [usdc_mint::id(), usdt_mint::id()] {
         let err = lending_market

token-lending/sdk/src/math/decimal.rs

@@ -57,7 +57,7 @@ impl Decimal {
 
     /// Create scaled decimal from bps value
     pub fn from_bps(bps: u64) -> Self {
-        Self(U192::from(bps * BPS_SCALER))
+        Self::from(bps).try_div(10_000).unwrap()
     }
 
     /// Return raw scaled value if it fits within u128
@@ -248,10 +248,8 @@ mod test {
 
     #[test]
     fn test_from_bps() {
-        let left = Decimal::from_bps(2000);
-        let right = Decimal::from_percent(20);
-
-        assert_eq!(left, right);
+        let left = Decimal::from_bps(190000);
+        assert_eq!(left, Decimal::from(19u64));
     }
 
     #[test]

token-lending/sdk/src/oracles.rs

@@ -56,6 +56,9 @@ pub fn get_pyth_price(
         let price_feed = price_account.to_price_feed(pyth_price_info.key);
         // this can be unchecked bc the ema price is only used to _limit_ borrows and withdraws.
         // ie staleness doesn't _really_ matter for this field.
+        //
+        // the pyth EMA is also updated every time the regular spot price is updated anyways so in
+        // reality the staleness should never be an issue.
         let ema_price = price_feed.get_ema_price_unchecked();
         pyth_price_to_decimal(&ema_price)?
     };

token-lending/sdk/src/state/lending_market.rs

@@ -65,8 +65,6 @@ pub struct InitLendingMarketParams {
     pub oracle_program_id: Pubkey,
     /// Oracle (Switchboard) program id
     pub switchboard_oracle_program_id: Pubkey,
-    /// Current slot
-    pub current_slot: u64,
 }
 
 impl Sealed for LendingMarket {}

token-lending/sdk/src/state/obligation.rs

@@ -49,8 +49,7 @@ pub struct Obligation {
     /// borrows and withdraws are disabled.
     pub allowed_borrow_value: Decimal,
     /// The dangerous borrow value at the weighted average liquidation threshold.
-    /// ie sum(d.deposited_amount * d.liquidation_threshold * min(d.current_spot_price, d.smoothed_price)
-    /// for d in deposits)
+    /// ie sum(d.deposited_amount * d.liquidation_threshold * d.current_spot_price for d in deposits)
     /// if borrowed_value >= unhealthy_borrow_value, the obligation can be liquidated
     pub unhealthy_borrow_value: Decimal,
 }