On 09/21/2016 08:41 AM, Riku Voipio wrote: > AFAIK Address space randomizing is not really helpful on 32 bit > architectures - there is just not that many places to randomize to[1].
Well, sure, but there's still a huge difference in an explot with 100% reliability, or an exploit that will just crash the program in 95% of cases. Sure, if there's an easy way to repeatedly try the exploit 20 times, it won't be a show-stopper, but it will make the life of people who want to exploit a flaw just a tiny bit harder. > At least previously, PIE added ~10% to binary size, At least on x86 there have been substantial improvements in receent gcc versions when it comes to PIE support, so the impact of PIE on executables even on 32bit is a lot smaller than it used to be. I don't know about ARM though. Consider the following two data points: - A _lot_ of code in Debian is in shared libraries, which are compiled with -fPIC anyway. Many executables only spend a fraction of their instructions in the executable code itself. - It's been considered best practice to enable PIE executables if possible (via hardening=+all or similar), so many programs in Debian (and e.g. all of my packages except one) already use that. I suspect that a lot of of code that you are currently running is already PIE, especially in the packages that are more actively maintained. Regards, Christian
