fix: check numbers of calls multicall precompile

cairo_zero/kakarot/errors.cairo

@@ -682,7 +682,7 @@ namespace Errors {
 
     func precompileInputError() -> (error_len: felt, error: felt*) {
         let (error) = get_label_location(precompile_input_error_message);
-        return (27, error);
+        return (23, error);
 
         precompile_input_error_message:
         dw 'P';
@@ -697,21 +697,17 @@ namespace Errors {
         dw 'e';
         dw ':';
         dw ' ';
-        dw 'w';
-        dw 'r';
-        dw 'o';
-        dw 'n';
-        dw 'g';
-        dw ' ';
         dw 'i';
         dw 'n';
         dw 'p';
         dw 'u';
         dw 't';
-        dw '_';
-        dw 'l';
+        dw ' ';
         dw 'e';
-        dw 'n';
+        dw 'r';
+        dw 'r';
+        dw 'o';
+        dw 'r';
     }
 
     func precompileFlagError() -> (error_len: felt, error: felt*) {

cairo_zero/kakarot/precompiles/kakarot_precompiles.cairo

@@ -34,7 +34,7 @@ const CAIRO_PRECOMPILE_GAS = 10000;
 // ! and the sending of transactions to L1.
 // !
 // ! There are various considerations that one must take into account when using these precompiles.
-// ! We currently have 4 different "precompiles".
+// ! We currently have 3 different "precompiles".
 // ! - 0x75001: Whitelisted Cairo Precompile. Allows any whitelisted caller to execute a Cairo call.
 // ! The whitelisting is based on the address of the caller. 75001 can be called using DELEGATECALL
 // ! / CALLCODE. Any contract calling 75001 must be whitelisted, as malicious contract would be able
@@ -107,6 +107,10 @@ namespace KakarotPrecompiles {
     // @param input_len The length of the input in bytes.
     // @param input The input data.
     // @param caller_address The address of the caller of the precompile.
+    // @returns output_len The length in bytes of the output of the first call that reverted else 0.
+    // @returns output The output data of the first call that reverted else empty.
+    // @returns gas_used The gas used.
+    // @returns reverted Errors.EXCEPTIONAL_HALT if a call reverted, FALSE otherwise.
     func cairo_multicall_precompile{
         syscall_ptr: felt*,
         pedersen_ptr: HashBuiltin*,
@@ -141,9 +145,17 @@ namespace KakarotPrecompiles {
         let calls_ptr = number_of_calls_ptr + NUMBER_OF_CALLS_BYTES;
         let calls_len = input_len - NUMBER_OF_CALLS_BYTES;
 
-        let (output_len, output, reverted) = Internals.execute_multiple_cairo_calls(
-            caller_address, calls_len, calls_ptr
-        );
+        let (
+            output_len, output, reverted, nb_executed_calls
+        ) = Internals.execute_multiple_cairo_calls(caller_address, calls_len, calls_ptr, 0);
+
+        if (reverted == FALSE and nb_executed_calls != number_of_calls) {
+            let (revert_reason_len, revert_reason) = Errors.precompileInputError();
+            return (
+                revert_reason_len, revert_reason, CAIRO_PRECOMPILE_GAS, Errors.EXCEPTIONAL_HALT
+            );
+        }
+
         return (output_len, output, gas_cost, reverted);
     }
 }
@@ -154,28 +166,31 @@ namespace Internals {
     // @param caller_address The address of the caller of the precompile.
     // @param calls_len The length of the calls array.
     // @param calls The calls to execute.
+    // @returns output_len The length in bytes of the output of the first call that reverted else 0.
+    // @returns output The output data of the first call that reverted else empty.
+    // @returns gas_used The gas used.
     // @returns reverted Errors.EXCEPTIONAL_HALT if reverted, FALSE otherwise.
     func execute_multiple_cairo_calls{
         syscall_ptr: felt*,
         pedersen_ptr: HashBuiltin*,
         range_check_ptr,
         bitwise_ptr: BitwiseBuiltin*,
-    }(caller_address: felt, calls_len: felt, calls: felt*) -> (
-        output_len: felt, output: felt*, reverted: felt
+    }(caller_address: felt, calls_len: felt, calls: felt*, nb_executed_calls: felt) -> (
+        output_len: felt, output: felt*, reverted: felt, nb_executed_calls: felt
     ) {
         alloc_locals;
 
         if (calls_len == 0) {
             let (output) = alloc();
-            return (0, output, FALSE);
+            return (0, output, FALSE, nb_executed_calls);
         }
 
         // Ensure that the current remaining calls_len >= MIN_EVM_ENCODED_STARKNET_CALL_BYTES
         // Otherwise the input is malformed
         let is_input_invalid = is_nn(MIN_EVM_ENCODED_STARKNET_CALL_BYTES - (calls_len + 1));
         if (is_input_invalid != 0) {
             let (revert_reason_len, revert_reason) = Errors.outOfBoundsRead();
-            return (revert_reason_len, revert_reason, Errors.EXCEPTIONAL_HALT);
+            return (revert_reason_len, revert_reason, Errors.EXCEPTIONAL_HALT, nb_executed_calls);
         }
 
         let (
@@ -184,20 +199,23 @@ namespace Internals {
 
         if (is_err != FALSE) {
             let (revert_reason_len, revert_reason) = Errors.precompileInputError();
-            return (revert_reason_len, revert_reason, Errors.EXCEPTIONAL_HALT);
+            return (revert_reason_len, revert_reason, Errors.EXCEPTIONAL_HALT, nb_executed_calls);
         }
 
         let (output_len, output, gas_used, reverted) = execute_cairo_call(
             caller_address, to_address, selector, calldata_len, calldata, skip_returndata=TRUE
         );
 
         if (reverted != FALSE) {
-            return (output_len, output, reverted);
+            return (output_len, output, reverted, nb_executed_calls + 1);
         }
 
         // Move to the next call
         return execute_multiple_cairo_calls(
-            caller_address, calls_len - next_call_offset, calls + next_call_offset
+            caller_address,
+            calls_len - next_call_offset,
+            calls + next_call_offset,
+            nb_executed_calls + 1,
         );
     }
 

cairo_zero/tests/src/kakarot/precompiles/test_blake2f.py

@@ -9,7 +9,7 @@
 class TestBlake2f:
     def test_should_fail_when_input_len_is_not_213(self, cairo_run):
         output = cairo_run("test_should_fail_when_input_is_not_213")
-        assert bytes(output) == b"Precompile: wrong input_len"
+        assert bytes(output) == b"Precompile: input error"
 
     def test_should_fail_when_flag_is_not_0_or_1(self, cairo_run):
         output = cairo_run("test_should_fail_when_flag_is_not_0_or_1")

tests/end_to_end/CairoPrecompiles/test_multicall_cairo_precompile.py

@@ -3,8 +3,9 @@
 import pytest
 import pytest_asyncio
 from eth_abi import encode
-from hypothesis import given, settings
+from hypothesis import assume, given, settings
 from hypothesis import strategies as st
+from starkware.cairo.lang.cairo_constants import DEFAULT_PRIME
 
 from kakarot_scripts.utils.kakarot import deploy, eth_send_transaction
 from kakarot_scripts.utils.starknet import get_contract, invoke
@@ -93,6 +94,30 @@ async def test_should_set_and_increase_counter_in_batch(
             expected_count = new_counter + 1
             assert new_count == expected_count
 
+        @given(wrong_nb_calls=st.integers(min_value=0, max_value=DEFAULT_PRIME - 1))
+        async def test_should_fail_when_number_of_calls_mismatch_actual_calls(
+            self, cairo_counter, owner, wrong_nb_calls
+        ):
+            assume(wrong_nb_calls != 2)
+            calls = [
+                cairo_counter.functions["set_counter"].prepare_call(1),
+                cairo_counter.functions["inc"].prepare_call(),
+            ]
+            tx_data = prepare_transaction_data(calls)
+            # modify the number of calls to be different than the actual calls
+            tx_data = f"{wrong_nb_calls:064x}" + tx_data[64:]
+
+            _, response, success, _ = await eth_send_transaction(
+                to=f"0x{0x75003:040x}",
+                gas=21000 + 20000 * (len(calls)),
+                data=tx_data,
+                value=0,
+                caller_eoa=owner.starknet_contract,
+            )
+
+            assert not success
+            assert "Precompile: input error".encode() == bytes(response)
+
         async def test_should_increase_counter_single_call_from_solidity(
             self, cairo_counter, multicall_cairo_counter_caller
         ):

tests/end_to_end/PlainOpcodes/test_plain_opcodes.py

@@ -416,7 +416,7 @@ class TestFallbackFunctions:
         async def test_should_revert_on_fallbacks(
             self, revert_on_fallbacks, data, value, message, other
         ):
-            receipt, response, success, gas_used = await eth_send_transaction(
+            _, response, success, _ = await eth_send_transaction(
                 to=revert_on_fallbacks.address,
                 gas=200_000,
                 data=data,