From 75284f12168391c5807ce0c76da822140bc97723 Mon Sep 17 00:00:00 2001
From: Alessandro Decina <alessandro.d@gmail.com>
Date: Thu, 27 Jul 2023 19:46:34 +0700
Subject: [PATCH] direct mapping: test that writes to executable accounts
 trigger ExecutableDataModified

---
 programs/sbf/rust/invoke/src/instructions.rs |  1 +
 programs/sbf/rust/invoke/src/processor.rs    |  7 +++
 programs/sbf/tests/programs.rs               | 53 ++++++++++++++++++++
 3 files changed, 61 insertions(+)

diff --git a/programs/sbf/rust/invoke/src/instructions.rs b/programs/sbf/rust/invoke/src/instructions.rs
index d7d833009c69ce..2da46b9ef21816 100644
--- a/programs/sbf/rust/invoke/src/instructions.rs
+++ b/programs/sbf/rust/invoke/src/instructions.rs
@@ -37,6 +37,7 @@ pub const TEST_CPI_INVALID_KEY_POINTER: u8 = 34;
 pub const TEST_CPI_INVALID_OWNER_POINTER: u8 = 35;
 pub const TEST_CPI_INVALID_LAMPORTS_POINTER: u8 = 36;
 pub const TEST_CPI_INVALID_DATA_POINTER: u8 = 37;
+pub const TEST_WRITE_ACCOUNT: u8 = 38;
 
 pub const MINT_INDEX: usize = 0;
 pub const ARGUMENT_INDEX: usize = 1;
diff --git a/programs/sbf/rust/invoke/src/processor.rs b/programs/sbf/rust/invoke/src/processor.rs
index 81f81ec0678465..b6d592f0f88a61 100644
--- a/programs/sbf/rust/invoke/src/processor.rs
+++ b/programs/sbf/rust/invoke/src/processor.rs
@@ -1220,6 +1220,13 @@ fn process_instruction(
             )
             .unwrap();
         }
+        TEST_WRITE_ACCOUNT => {
+            msg!("TEST_WRITE_ACCOUNT");
+            let target_account_index = instruction_data[1] as usize;
+            let target_account = &accounts[target_account_index];
+            let byte_index = usize::from_le_bytes(instruction_data[2..10].try_into().unwrap());
+            target_account.data.borrow_mut()[byte_index] = instruction_data[10];
+        }
         _ => panic!("unexpected program data"),
     }
 
diff --git a/programs/sbf/tests/programs.rs b/programs/sbf/tests/programs.rs
index 8e5c7aa104c20b..f723c8f08ea20b 100644
--- a/programs/sbf/tests/programs.rs
+++ b/programs/sbf/tests/programs.rs
@@ -4440,3 +4440,56 @@ fn test_cpi_invalid_account_info_pointers() {
         }
     }
 }
+
+#[test]
+#[cfg(feature = "sbf_rust")]
+fn test_deny_executable_write() {
+    solana_logger::setup();
+
+    let GenesisConfigInfo {
+        genesis_config,
+        mint_keypair,
+        ..
+    } = create_genesis_config(100_123_456_789);
+
+    for direct_mapping in [false, true] {
+        let mut bank = Bank::new_for_tests(&genesis_config);
+        let feature_set = Arc::make_mut(&mut bank.feature_set);
+        // by default test banks have all features enabled, so we only need to
+        // disable when needed
+        if !direct_mapping {
+            feature_set.deactivate(&feature_set::bpf_account_data_direct_mapping::id());
+        }
+        let bank = Arc::new(bank);
+        let mut bank_client = BankClient::new_shared(bank);
+
+        let (_bank, invoke_program_id) = load_program_and_advance_slot(
+            &mut bank_client,
+            &bpf_loader::id(),
+            &mint_keypair,
+            "solana_sbf_rust_invoke",
+        );
+
+        let account_keypair = Keypair::new();
+        let mint_pubkey = mint_keypair.pubkey();
+        let account_metas = vec![
+            AccountMeta::new(mint_pubkey, true),
+            AccountMeta::new(account_keypair.pubkey(), false),
+            AccountMeta::new_readonly(invoke_program_id, false),
+        ];
+
+        let mut instruction_data = vec![TEST_WRITE_ACCOUNT, 2];
+        instruction_data.extend_from_slice(4usize.to_le_bytes().as_ref());
+        instruction_data.push(42);
+        let instruction = Instruction::new_with_bytes(
+            invoke_program_id,
+            &instruction_data,
+            account_metas.clone(),
+        );
+        let result = bank_client.send_and_confirm_instruction(&mint_keypair, instruction);
+        assert_eq!(
+            result.unwrap_err().unwrap(),
+            TransactionError::InstructionError(0, InstructionError::ExecutableDataModified)
+        );
+    }
+}