Return error if Transaction contains writable executable or ProgramData accounts (#19629)

* Return error if Transaction locks an executable as writable

* Return error if a ProgramData account is writable but the upgradable loader isn't present

* Remove unreachable clause

* Fixup bpf tests

* Review comments

* Add new TransactionError

* Disallow writes to any upgradeable-loader account when loader not present; remove is_upgradeable_loader_present exception for all other executables

runtime/src/accounts.rs

@@ -241,6 +241,7 @@ impl Accounts {
             let rent_for_sysvars = feature_set.is_active(&feature_set::rent_for_sysvars::id());
             let demote_program_write_locks =
                 feature_set.is_active(&feature_set::demote_program_write_locks::id());
+            let is_upgradeable_loader_present = is_upgradeable_loader_present(message);
 
             for (i, key) in message.account_keys_iter().enumerate() {
                 let account = if message.is_non_loader_key(i) {
@@ -249,9 +250,6 @@ impl Accounts {
                     }
 
                     if solana_sdk::sysvar::instructions::check_id(key) {
-                        if message.is_writable(i, demote_program_write_locks) {
-                            return Err(TransactionError::InvalidAccountIndex);
-                        }
                         Self::construct_instructions_account(
                             message,
                             feature_set
@@ -276,27 +274,42 @@ impl Accounts {
                             })
                             .unwrap_or_default();
 
-                        if account.executable() && bpf_loader_upgradeable::check_id(account.owner())
-                        {
-                            // The upgradeable loader requires the derived ProgramData account
-                            if let Ok(UpgradeableLoaderState::Program {
-                                programdata_address,
-                            }) = account.state()
+                        if bpf_loader_upgradeable::check_id(account.owner()) {
+                            if demote_program_write_locks
+                                && message.is_writable(i, demote_program_write_locks)
+                                && !is_upgradeable_loader_present
                             {
-                                if let Some(account) = self
-                                    .accounts_db
-                                    .load_with_fixed_root(ancestors, &programdata_address)
-                                    .map(|(account, _)| account)
-                                {
-                                    account_deps.push((programdata_address, account));
-                                } else {
-                                    error_counters.account_not_found += 1;
-                                    return Err(TransactionError::ProgramAccountNotFound);
-                                }
-                            } else {
-                                error_counters.invalid_program_for_execution += 1;
-                                return Err(TransactionError::InvalidProgramForExecution);
+                                error_counters.invalid_writable_account += 1;
+                                return Err(TransactionError::InvalidWritableAccount);
                             }
+
+                            if account.executable() {
+                                // The upgradeable loader requires the derived ProgramData account
+                                if let Ok(UpgradeableLoaderState::Program {
+                                    programdata_address,
+                                }) = account.state()
+                                {
+                                    if let Some(account) = self
+                                        .accounts_db
+                                        .load_with_fixed_root(ancestors, &programdata_address)
+                                        .map(|(account, _)| account)
+                                    {
+                                        account_deps.push((programdata_address, account));
+                                    } else {
+                                        error_counters.account_not_found += 1;
+                                        return Err(TransactionError::ProgramAccountNotFound);
+                                    }
+                                } else {
+                                    error_counters.invalid_program_for_execution += 1;
+                                    return Err(TransactionError::InvalidProgramForExecution);
+                                }
+                            }
+                        } else if account.executable()
+                            && demote_program_write_locks
+                            && message.is_writable(i, demote_program_write_locks)
+                        {
+                            error_counters.invalid_writable_account += 1;
+                            return Err(TransactionError::InvalidWritableAccount);
                         }
 
                         tx_rent += rent;
@@ -1104,6 +1117,12 @@ pub fn prepare_if_nonce_account(
     false
 }
 
+fn is_upgradeable_loader_present(message: &SanitizedMessage) -> bool {
+    message
+        .account_keys_iter()
+        .any(|&key| key == bpf_loader_upgradeable::id())
+}
+
 pub fn create_test_accounts(
     accounts: &Accounts,
     pubkeys: &mut Vec<Pubkey>,
@@ -1680,6 +1699,247 @@ mod tests {
         assert_eq!(loaded, vec![]);
     }
 
+    #[test]
+    fn test_load_accounts_executable_with_write_lock() {
+        let mut accounts: Vec<(Pubkey, AccountSharedData)> = Vec::new();
+        let mut error_counters = ErrorCounters::default();
+
+        let keypair = Keypair::new();
+        let key0 = keypair.pubkey();
+        let key1 = Pubkey::new(&[5u8; 32]);
+        let key2 = Pubkey::new(&[6u8; 32]);
+
+        let mut account = AccountSharedData::new(1, 0, &Pubkey::default());
+        account.set_rent_epoch(1);
+        accounts.push((key0, account));
+
+        let mut account = AccountSharedData::new(40, 1, &native_loader::id());
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((key1, account));
+
+        let mut account = AccountSharedData::new(40, 1, &native_loader::id());
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((key2, account));
+
+        let instructions = vec![CompiledInstruction::new(2, &(), vec![0, 1])];
+        let mut message = Message::new_with_compiled_instructions(
+            1,
+            0,
+            1, // only one executable marked as readonly
+            vec![key0, key1, key2],
+            Hash::default(),
+            instructions,
+        );
+        let tx = Transaction::new(&[&keypair], message.clone(), Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        assert_eq!(
+            loaded_accounts[0],
+            (Err(TransactionError::InvalidWritableAccount), None)
+        );
+
+        // Mark executables as readonly
+        message.account_keys = vec![key0, key1, key2]; // revert key change
+        message.header.num_readonly_unsigned_accounts = 2; // mark both executables as readonly
+        let tx = Transaction::new(&[&keypair], message, Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        let result = loaded_accounts[0].0.as_ref().unwrap();
+        assert_eq!(result.accounts[..2], accounts[..2]);
+        assert_eq!(result.loaders[0], vec![accounts[2].clone()]);
+    }
+
+    #[test]
+    fn test_load_accounts_upgradeable_with_write_lock() {
+        let mut accounts: Vec<(Pubkey, AccountSharedData)> = Vec::new();
+        let mut error_counters = ErrorCounters::default();
+
+        let keypair = Keypair::new();
+        let key0 = keypair.pubkey();
+        let key1 = Pubkey::new(&[5u8; 32]);
+        let key2 = Pubkey::new(&[6u8; 32]);
+        let programdata_key1 = Pubkey::new(&[7u8; 32]);
+        let programdata_key2 = Pubkey::new(&[8u8; 32]);
+
+        let mut account = AccountSharedData::new(1, 0, &Pubkey::default());
+        account.set_rent_epoch(1);
+        accounts.push((key0, account));
+
+        let program_data = UpgradeableLoaderState::ProgramData {
+            slot: 42,
+            upgrade_authority_address: None,
+        };
+
+        let program = UpgradeableLoaderState::Program {
+            programdata_address: programdata_key1,
+        };
+        let mut account =
+            AccountSharedData::new_data(40, &program, &bpf_loader_upgradeable::id()).unwrap();
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((key1, account));
+        let mut account =
+            AccountSharedData::new_data(40, &program_data, &bpf_loader_upgradeable::id()).unwrap();
+        account.set_rent_epoch(1);
+        accounts.push((programdata_key1, account));
+
+        let program = UpgradeableLoaderState::Program {
+            programdata_address: programdata_key2,
+        };
+        let mut account =
+            AccountSharedData::new_data(40, &program, &bpf_loader_upgradeable::id()).unwrap();
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((key2, account));
+        let mut account =
+            AccountSharedData::new_data(40, &program_data, &bpf_loader_upgradeable::id()).unwrap();
+        account.set_rent_epoch(1);
+        accounts.push((programdata_key2, account));
+
+        let mut account = AccountSharedData::new(40, 1, &native_loader::id()); // create mock bpf_loader_upgradeable
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((bpf_loader_upgradeable::id(), account));
+
+        let instructions = vec![CompiledInstruction::new(2, &(), vec![0, 1])];
+        let mut message = Message::new_with_compiled_instructions(
+            1,
+            0,
+            1, // only one executable marked as readonly
+            vec![key0, key1, key2],
+            Hash::default(),
+            instructions,
+        );
+        let tx = Transaction::new(&[&keypair], message.clone(), Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        assert_eq!(
+            loaded_accounts[0],
+            (Err(TransactionError::InvalidWritableAccount), None)
+        );
+
+        // Solution 1: include bpf_loader_upgradeable account
+        message.account_keys = vec![key0, key1, bpf_loader_upgradeable::id()];
+        let tx = Transaction::new(&[&keypair], message.clone(), Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        let result = loaded_accounts[0].0.as_ref().unwrap();
+        assert_eq!(result.accounts[..2], accounts[..2]);
+        assert_eq!(result.loaders[0], vec![accounts[5].clone()]);
+
+        // Solution 2: mark programdata as readonly
+        message.account_keys = vec![key0, key1, key2]; // revert key change
+        message.header.num_readonly_unsigned_accounts = 2; // mark both executables as readonly
+        let tx = Transaction::new(&[&keypair], message, Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        let result = loaded_accounts[0].0.as_ref().unwrap();
+        assert_eq!(result.accounts[..2], accounts[..2]);
+        assert_eq!(
+            result.loaders[0],
+            vec![
+                accounts[5].clone(),
+                accounts[3].clone(),
+                accounts[4].clone()
+            ]
+        );
+    }
+
+    #[test]
+    fn test_load_accounts_programdata_with_write_lock() {
+        let mut accounts: Vec<(Pubkey, AccountSharedData)> = Vec::new();
+        let mut error_counters = ErrorCounters::default();
+
+        let keypair = Keypair::new();
+        let key0 = keypair.pubkey();
+        let key1 = Pubkey::new(&[5u8; 32]);
+        let key2 = Pubkey::new(&[6u8; 32]);
+
+        let mut account = AccountSharedData::new(1, 0, &Pubkey::default());
+        account.set_rent_epoch(1);
+        accounts.push((key0, account));
+
+        let program_data = UpgradeableLoaderState::ProgramData {
+            slot: 42,
+            upgrade_authority_address: None,
+        };
+        let mut account =
+            AccountSharedData::new_data(40, &program_data, &bpf_loader_upgradeable::id()).unwrap();
+        account.set_rent_epoch(1);
+        accounts.push((key1, account));
+
+        let mut account = AccountSharedData::new(40, 1, &native_loader::id());
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        accounts.push((key2, account));
+
+        let instructions = vec![CompiledInstruction::new(2, &(), vec![0, 1])];
+        let mut message = Message::new_with_compiled_instructions(
+            1,
+            0,
+            1, // only the program marked as readonly
+            vec![key0, key1, key2],
+            Hash::default(),
+            instructions,
+        );
+        let tx = Transaction::new(&[&keypair], message.clone(), Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        assert_eq!(
+            loaded_accounts[0],
+            (Err(TransactionError::InvalidWritableAccount), None)
+        );
+
+        // Solution 1: include bpf_loader_upgradeable account
+        let mut account = AccountSharedData::new(40, 1, &native_loader::id()); // create mock bpf_loader_upgradeable
+        account.set_executable(true);
+        account.set_rent_epoch(1);
+        let accounts_with_upgradeable_loader = vec![
+            accounts[0].clone(),
+            accounts[1].clone(),
+            (bpf_loader_upgradeable::id(), account),
+        ];
+        message.account_keys = vec![key0, key1, bpf_loader_upgradeable::id()];
+        let tx = Transaction::new(&[&keypair], message.clone(), Hash::default());
+        let loaded_accounts =
+            load_accounts(tx, &accounts_with_upgradeable_loader, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        let result = loaded_accounts[0].0.as_ref().unwrap();
+        assert_eq!(result.accounts[..2], accounts_with_upgradeable_loader[..2]);
+        assert_eq!(
+            result.loaders[0],
+            vec![accounts_with_upgradeable_loader[2].clone()]
+        );
+
+        // Solution 2: mark programdata as readonly
+        message.account_keys = vec![key0, key1, key2]; // revert key change
+        message.header.num_readonly_unsigned_accounts = 2; // extend readonly set to include programdata
+        let tx = Transaction::new(&[&keypair], message, Hash::default());
+        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
+
+        assert_eq!(error_counters.invalid_writable_account, 1);
+        assert_eq!(loaded_accounts.len(), 1);
+        let result = loaded_accounts[0].0.as_ref().unwrap();
+        assert_eq!(result.accounts[..2], accounts[..2]);
+        assert_eq!(result.loaders[0], vec![accounts[2].clone()]);
+    }
+
     #[test]
     fn test_accounts_account_not_found() {
         let accounts = Accounts::new_with_config_for_tests(