ICC stack-security-check

Recently I've been playing with the Intel C++/C Compiler. Code produced by the compiler reportedly are optimized better than GCC's. I'd say it's overrated and only gives perceived speed increase for common use.

I noticed that by default it produces AT&T assembly instead of Intel. Anyway, I'm more interested in its security feature.

$ icc -help
...
-fstack-security-check
              enable overflow security checks
...

A sample C program I used.

int 
main(int argc,char *argv[]) {
  char buffer[256];
  strcpy(buffer,argv[1]);
  return 0;
}

This is the vanilla assembly output of the program above.

push   ebp
mov    ebp,esp
sub    esp,0x3
and    esp,0xfffffff8
add    esp,0x4
sub    esp,0x108
add    esp,0x0
lea    eax,[ebp-0x100]
mov    DWORD PTR [esp],eax
mov    eax,DWORD PTR [ebp+0xc]
mov    eax,DWORD PTR [eax+0x4]
mov    DWORD PTR [esp+0x4],eax
call   804ddd0 <strcpy>
add    esp,0x8
xor    eax,eax
leave
ret

Looking at the produced assembly output of -fstack-security-check, it looks very similar to Stack Smashing Protector (SSP).

[chunk 1]
<         sub    esp,0x108
---
>         sub    esp,0x10c
>         mov    eax,__intel_security_cookie
>         mov    eax,DWORD PTR [ebp-0x4]
[chunk 2]
<         lea    eax,[ebp-0x100]
---
>         lea    eax,[ebp-0x104]
[chunk 3]
>         mov    eax,DWORD PTR [ebp-0x4]
>         call   __intel_security_check_cookie

__intel_security_cookie is a 32-bit canary from DS e.g. ds:0x080bc00c. Just like SSP it checks the canary before returning.

./dumbsoft `ruby -e 'puts "B"*512'`
Error:  Buffer overrun occurred, forced exit
Aborted

In case you didn't know, GCC has similar features.