Revert "Reject vote withdraws that create non-rent-exempt accounts (backport #21639) (#21644)"

This reverts commit 83e01442a7.

programs/vote/src/vote_instruction.rs

@@ -16,7 +16,7 @@ use {
         hash::Hash,
         instruction::{AccountMeta, Instruction, InstructionError},
         keyed_account::{from_keyed_account, get_signers, keyed_account_at_index, KeyedAccount},
-        process_instruction::{get_sysvar, InvokeContext},
+        process_instruction::InvokeContext,
         program_utils::limited_deserialize,
         pubkey::Pubkey,
         system_instruction,
@@ -366,14 +366,7 @@ pub fn process_instruction(
         }
         VoteInstruction::Withdraw(lamports) => {
             let to = keyed_account_at_index(keyed_accounts, 1)?;
-            let rent_sysvar = if invoke_context
+            vote_state::withdraw(me, lamports, to, &signers)
-                .is_feature_active(&feature_set::reject_non_rent_exempt_vote_withdraws::id())
-            {
-                Some(get_sysvar(invoke_context, &sysvar::rent::id())?)
-            } else {
-                None
-            };
-            vote_state::withdraw(me, lamports, to, &signers, rent_sysvar)
         }
         VoteInstruction::AuthorizeChecked(vote_authorize) => {
             if invoke_context.is_feature_active(&feature_set::vote_stake_checked_instructions::id())
@@ -402,7 +395,7 @@ mod tests {
         bincode::serialize,
         solana_sdk::{
             account::{self, Account, AccountSharedData},
-            process_instruction::{mock_set_sysvar, MockInvokeContext},
+            process_instruction::MockInvokeContext,
             rent::Rent,
         },
         std::{cell::RefCell, str::FromStr},
@@ -461,14 +454,11 @@ mod tests {
                 .zip(accounts.iter())
                 .map(|(meta, account)| KeyedAccount::new(&meta.pubkey, meta.is_signer, account))
                 .collect();
-            let mut invoke_context = MockInvokeContext::new(keyed_accounts);
+            super::process_instruction(
-            mock_set_sysvar(
+                &Pubkey::default(),
-                &mut invoke_context,
+                &instruction.data,
-                sysvar::rent::id(),
+                &mut MockInvokeContext::new(keyed_accounts),
-                sysvar::rent::Rent::default(),
             )
-            .unwrap();
-            super::process_instruction(&Pubkey::default(), &instruction.data, &mut invoke_context)
         }
     }
 

programs/vote/src/vote_state/mod.rs

@@ -20,6 +20,7 @@ use {
     },
     std::{
         boxed::Box,
+        cmp::Ordering,
         collections::{HashSet, VecDeque},
     },
 };
@@ -681,28 +682,20 @@ pub fn withdraw<S: std::hash::BuildHasher>(
     lamports: u64,
     to_account: &KeyedAccount,
     signers: &HashSet<Pubkey, S>,
-    rent_sysvar: Option<Rent>,
 ) -> Result<(), InstructionError> {
     let vote_state: VoteState =
         State::<VoteStateVersions>::state(vote_account)?.convert_to_current();
 
     verify_authorized_signer(&vote_state.authorized_withdrawer, signers)?;
 
-    let remaining_balance = vote_account
+    match vote_account.lamports()?.cmp(&lamports) {
-        .lamports()?
+        Ordering::Less => return Err(InstructionError::InsufficientFunds),
-        .checked_sub(lamports)
+        Ordering::Equal => {
-        .ok_or(InstructionError::InsufficientFunds)?;
+            // Deinitialize upon zero-balance
-
+            vote_account.set_state(&VoteStateVersions::new_current(VoteState::default()))?;
-    if remaining_balance == 0 {
-        // Deinitialize upon zero-balance
-        vote_account.set_state(&VoteStateVersions::new_current(VoteState::default()))?;
-    } else if let Some(rent_sysvar) = rent_sysvar {
-        let min_rent_exempt_balance = rent_sysvar.minimum_balance(vote_account.data_len()?);
-        if remaining_balance < min_rent_exempt_balance {
-            return Err(InstructionError::InsufficientFunds);
         }
+        _ => (),
     }
-
     vote_account
         .try_account_ref_mut()?
         .checked_sub_lamports(lamports)?;
@@ -906,8 +899,6 @@ mod tests {
     }
 
     fn create_test_account() -> (Pubkey, RefCell<AccountSharedData>) {
-        let rent = Rent::default();
-        let balance = VoteState::get_rent_exempt_reserve(&rent);
         let vote_pubkey = solana_sdk::pubkey::new_rand();
         (
             vote_pubkey,
@@ -915,7 +906,7 @@ mod tests {
                 &vote_pubkey,
                 &solana_sdk::pubkey::new_rand(),
                 0,
-                balance,
+                100,
             )),
         )
     }
@@ -1676,129 +1667,46 @@ mod tests {
                 &RefCell::new(AccountSharedData::default()),
             ),
             &signers,
-            None,
         );
         assert_eq!(res, Err(InstructionError::MissingRequiredSignature));
 
         // insufficient funds
         let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
-        let lamports = vote_account.borrow().lamports();
         let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
         let res = withdraw(
             &keyed_accounts[0],
-            lamports + 1,
+            101,
             &KeyedAccount::new(
                 &solana_sdk::pubkey::new_rand(),
                 false,
                 &RefCell::new(AccountSharedData::default()),
             ),
             &signers,
-            None,
         );
         assert_eq!(res, Err(InstructionError::InsufficientFunds));
 
-        // non rent exempt withdraw, before feature activation
+        // all good
-        {
+        let to_account = RefCell::new(AccountSharedData::default());
-            let (vote_pubkey, vote_account) = create_test_account();
+        let lamports = vote_account.borrow().lamports();
-            let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
+        let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
-            let lamports = vote_account.borrow().lamports();
+        let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
-            let rent_sysvar = Rent::default();
+        let pre_state: VoteStateVersions = vote_account.borrow().state().unwrap();
-            let minimum_balance = rent_sysvar
+        let res = withdraw(
-                .minimum_balance(vote_account.borrow().data().len())
+            &keyed_accounts[0],
-                .max(1);
+            lamports,
-            assert!(minimum_balance <= lamports);
+            &KeyedAccount::new(&solana_sdk::pubkey::new_rand(), false, &to_account),
-            let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
+            &signers,
-            let res = withdraw(
+        );
-                &keyed_accounts[0],
+        assert_eq!(res, Ok(()));
-                lamports - minimum_balance + 1,
+        assert_eq!(vote_account.borrow().lamports(), 0);
-                &KeyedAccount::new(
+        assert_eq!(to_account.borrow().lamports(), lamports);
-                    &solana_sdk::pubkey::new_rand(),
+        let post_state: VoteStateVersions = vote_account.borrow().state().unwrap();
-                    false,
+        // State has been deinitialized since balance is zero
-                    &RefCell::new(AccountSharedData::default()),
+        assert!(post_state.is_uninitialized());
-                ),
-                &signers,
-                None,
-            );
-            assert_eq!(res, Ok(()));
-        }
 
-        // non rent exempt withdraw, after feature activation
+        // reset balance and restore state, verify that authorized_withdrawer works
-        {
+        vote_account.borrow_mut().set_lamports(lamports);
-            let (vote_pubkey, vote_account) = create_test_account();
+        vote_account.borrow_mut().set_state(&pre_state).unwrap();
-            let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
-            let lamports = vote_account.borrow().lamports();
-            let rent_sysvar = Rent::default();
-            let minimum_balance = rent_sysvar
-                .minimum_balance(vote_account.borrow().data().len())
-                .max(1);
-            assert!(minimum_balance <= lamports);
-            let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
-            let res = withdraw(
-                &keyed_accounts[0],
-                lamports - minimum_balance + 1,
-                &KeyedAccount::new(
-                    &solana_sdk::pubkey::new_rand(),
-                    false,
-                    &RefCell::new(AccountSharedData::default()),
-                ),
-                &signers,
-                Some(rent_sysvar),
-            );
-            assert_eq!(res, Err(InstructionError::InsufficientFunds));
-        }
-
-        // partial valid withdraw, after feature activation
-        {
-            let to_account = RefCell::new(AccountSharedData::default());
-            let (vote_pubkey, vote_account) = create_test_account();
-            let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
-            let lamports = vote_account.borrow().lamports();
-            let rent_sysvar = Rent::default();
-            let minimum_balance = rent_sysvar
-                .minimum_balance(vote_account.borrow().data().len())
-                .max(1);
-            assert!(minimum_balance <= lamports);
-            let withdraw_lamports = lamports - minimum_balance;
-            let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
-            let res = withdraw(
-                &keyed_accounts[0],
-                withdraw_lamports,
-                &KeyedAccount::new(&solana_sdk::pubkey::new_rand(), false, &to_account),
-                &signers,
-                Some(rent_sysvar),
-            );
-            assert_eq!(res, Ok(()));
-            assert_eq!(
-                vote_account.borrow().lamports(),
-                lamports - withdraw_lamports
-            );
-            assert_eq!(to_account.borrow().lamports(), withdraw_lamports);
-        }
-
-        // full withdraw, before/after activation
-        {
-            let rent_sysvar = Rent::default();
-            for rent_sysvar in &[None, Some(rent_sysvar)] {
-                let to_account = RefCell::new(AccountSharedData::default());
-                let (vote_pubkey, vote_account) = create_test_account();
-                let lamports = vote_account.borrow().lamports();
-                let keyed_accounts = &[KeyedAccount::new(&vote_pubkey, true, &vote_account)];
-                let signers: HashSet<Pubkey> = get_signers(keyed_accounts);
-                let res = withdraw(
-                    &keyed_accounts[0],
-                    lamports,
-                    &KeyedAccount::new(&solana_sdk::pubkey::new_rand(), false, &to_account),
-                    &signers,
-                    *rent_sysvar,
-                );
-                assert_eq!(res, Ok(()));
-                assert_eq!(vote_account.borrow().lamports(), 0);
-                assert_eq!(to_account.borrow().lamports(), lamports);
-                let post_state: VoteStateVersions = vote_account.borrow().state().unwrap();
-                // State has been deinitialized since balance is zero
-                assert!(post_state.is_uninitialized());
-            }
-        }
 
         // authorize authorized_withdrawer
         let authorized_withdrawer_pubkey = solana_sdk::pubkey::new_rand();
@@ -1827,7 +1735,6 @@ mod tests {
             lamports,
             withdrawer_keyed_account,
             &signers,
-            None,
         );
         assert_eq!(res, Ok(()));
         assert_eq!(vote_account.borrow().lamports(), 0);

sdk/src/feature_set.rs

@@ -273,10 +273,6 @@ pub mod reject_section_virtual_address_file_offset_mismatch {
     solana_sdk::declare_id!("5N4NikcJLEiZNqwndhNyvZw15LvFXp1oF7AJQTNTZY5k");
 }
 
-pub mod reject_non_rent_exempt_vote_withdraws {
-    solana_sdk::declare_id!("7txXZZD6Um59YoLMF7XUNimbMjsqsWhc7g2EniiTrmp1");
-}
-
 lazy_static! {
     /// Map of feature identifiers to user-visible description
     pub static ref FEATURE_NAMES: HashMap<Pubkey, &'static str> = [
@@ -345,7 +341,6 @@ lazy_static! {
         (spl_token_v3_3_0_release::id(), "spl-token v3.3.0 release"),
         (reject_deployment_of_unresolved_syscalls::id(), "Reject deployment of programs with unresolved syscall symbols"),
         (reject_section_virtual_address_file_offset_mismatch::id(), "enforce section virtual addresses and file offsets in ELF to be equal"),
-        (reject_non_rent_exempt_vote_withdraws::id(), "fail vote withdraw instructions which leave the account non-rent-exempt"),
         /*************** ADD NEW FEATURES HERE ***************/
     ]
     .iter()