Dynamic array program crashes when printing in Nasm Assembly - arrays

Question

I am trying to write a nasm program that can move and print dynamic arrays using malloc and printf. The program sometimes crashes and sometimes works when it tries to print an array. When I edit the code so that it doesn't print anything, the program always works. The method "movad" sets a dynamic array equal to another array and "setad" sets an array to a static array that was declared at the beginning of the program. The array variable stores a pointer to a malloced piece of memory that stores the array. The first dword of the array is the length and the rest is the contents.
Here is the code:
%include "io.inc"
CEXTERN malloc
section .data
fmt: db "%c%c %c%c",0
start: dd 2
dd 'a'
dd 'b'
section .bss
array1: resd 1
array2: resd 1
a: resd 1
section .text
global _main
_main:
push ebp
mov ebp,esp
push dword start
push dword array1
call setad
add esp,8
push dword array1
push dword array2
call movad
add esp,8
mov ebx,[array2]
push dword [ebx+8]
push dword [ebx+4]
mov ebx,[array1]
push dword [ebx+8]
push dword [ebx+4]
push dword fmt
call printf
add esp,20
mov esp,ebp
pop ebp
ret
movad:
push ebp
mov ebp,esp
push ebx
push ecx
push edi
push esi
mov edi,[ebp+8]
mov esi,[ebp+12]
mov ebx,[esi]
push dword [ebx]
add dword [esp],4
call malloc
add esp,4
mov [edi],eax
mov ecx,[esi]
mov ecx,[ecx]
add ecx,1
mov edi,[edi]
mov esi,[esi]
cld
rep movsd
pop esi
pop edi
pop ecx
pop ebx
mov esp,ebp
pop ebp
ret
setad:
push ebp
mov ebp,esp
push eax
lea eax,[ebp+12]
push eax
push dword [ebp+8]
call movad
add esp,8
pop eax
mov esp,ebp
pop ebp
ret
How can I make it so that it never crashes when it prints something