Add SystemInstruction::CreateAccount support to CPI (#11649)

sdk/bpf/c/inc/solana_sdk.h

@@ -256,6 +256,11 @@ typedef struct {
   const SolPubkey *program_id; /** program_id of the currently executing program */
 } SolParameters;
 
+/**
+ * Maximum number of bytes a program may add to an account during a single realloc
+ */
+#define MAX_PERMITTED_DATA_INCREASE (1024 * 10)
+
 /**
  * De-serializes the input parameters into usable types
  *
@@ -297,6 +302,7 @@ static bool sol_deserialize(
         uint64_t data_len = *(uint64_t *) input;
         input += sizeof(uint64_t);
         input += data_len;
+        input += MAX_PERMITTED_DATA_INCREASE;
         input = (uint8_t*)(((uint64_t)input + 8 - 1) & ~(8 - 1)); // padding
         input += sizeof(uint64_t);
       }
@@ -334,6 +340,7 @@ static bool sol_deserialize(
       input += sizeof(uint64_t);
       params->ka[i].data = (uint8_t *) input;
       input += params->ka[i].data_len;
+      input += MAX_PERMITTED_DATA_INCREASE;
       input = (uint8_t*)(((uint64_t)input + 8 - 1) & ~(8 - 1)); // padding
 
       // rent epoch

sdk/src/entrypoint.rs

@@ -48,6 +48,9 @@ macro_rules! entrypoint {
     };
 }
 
+/// Maximum number of bytes a program may add to an account during a single realloc
+pub const MAX_PERMITTED_DATA_INCREASE: usize = 1_024 * 10;
+
 /// Deserialize the input arguments
 ///
 /// # Safety
@@ -99,7 +102,7 @@ pub unsafe fn deserialize<'a>(input: *mut u8) -> (&'a Pubkey, Vec<AccountInfo<'a
             let data = Rc::new(RefCell::new({
                 from_raw_parts_mut(input.add(offset), data_len)
             }));
-            offset += data_len;
+            offset += data_len + MAX_PERMITTED_DATA_INCREASE;
             offset += (offset as *const u8).align_offset(align_of::<u128>()); // padding
 
             #[allow(clippy::cast_ptr_alignment)]

sdk/src/instruction.rs

@@ -159,6 +159,10 @@ pub enum InstructionError {
     /// Provided seeds do not result in a valid address
     #[error("Provided seeds do not result in a valid address")]
     InvalidSeeds,
+
+    // Failed to reallocate account data of this length
+    #[error("Failed to reallocate account data")]
+    InvalidRealloc,
 }
 
 #[derive(Debug, PartialEq, Clone)]