randomize_va_space values

Kernel version

cyrus@ubuntu:/$ uname -a
Linux ubuntu 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:24 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
cyrus@ubuntu:/$ 

randomize_va_space default value
cyrus@ubuntu:/$ cat /proc/sys/kernel/randomize_va_space
2
cyrus@ubuntu:/$ 

randomize_va_space values
0: No randomization of address space.
1: Conservative address space randomization. Code start register will be randomized.
2: Full address space randomization. Contains the feature of value 1 in addition brk area is randomized.

Virtual memory
Each program will have exactly the same memory structure, making hardcoding of instruction and push the instruction to the fixed memory space easier.
With address space randomization, each execution of a program will be residing in different starting addresses. This makes hardcoding and pushing of hardcoded instruction to the predicted memory space harder.

Reference: http://www.kernel.org/pub/linux/kernel/people/jikos/randomization/brk-fix-2.patch
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One Response to randomize_va_space values

  1. robin says:

    good 1 🙂

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