This is the example code:

#include <mpi.h>

#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  int size, rank;
  const int root = 0;

  int datasize = atoi(argv[1]);

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &size);
  MPI_Comm_rank(MPI_COMM_WORLD, &rank);

  int nodeDest = rank + 1;
  if (nodeDest > size - 1) {
    nodeDest = 0;
  }
  int nodeFrom = rank - 1;
  if (nodeFrom < 0) {
    nodeFrom = size - 1;
  }

  MPI_Status status;
  MPI_Request req[2];

  int *data = new int[datasize];
  int *data2 = new int[datasize];
  for (int i = 0; i < datasize; i++) data[i] = rank;


  cout << "Before send" << endl;
  MPI_Isend(data, datasize, MPI_INT, nodeDest, 0, MPI_COMM_WORLD, &req[0]);
  delete[] data;
  cout << "After send" << endl;
  MPI_Recv(data2, datasize, MPI_INT, nodeFrom, 0, MPI_COMM_WORLD,&status);
  cout << "After Irecv" << endl;
  MPI_Wait(&req[0], MPI_STATUS_IGNORE);
  cout << "After wait" << endl;

  delete[] data2;

  MPI_Finalize();
  return 0;
}

I use mpich-4.1.2 and intel mpi(oneAPI 2020). When the buffer size is small, both are ok.

mpirun -np 4 ./test 100
/opt/intel/compilers_and_libraries_2020.0.139/linux/mpi/intel64/bin/mpirun -np 4 ./test 100

But when the buffer size is huge, mpich got EXIT CODE: 9

mpirun -np 4 ./test 100000
Before send
Before send
After send
Before sendBefore send
After send
After send

After send

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   PID 321877 RUNNING AT 
=   EXIT CODE: 9
=   CLEANING UP REMAINING PROCESSES
=   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Segmentation fault (signal 11)
This typically refers to a problem with your application.
Please see the FAQ page for debugging suggestions

I know what caused this problem is line delete[] data; , but not clear about the details behind it.