File:  [NetBSD Developer Wiki] / wikisrc / security / kaslr.mdwn
Revision 1.1: download - view: text, annotated - select for diffs
Thu Aug 2 17:24:41 2018 UTC (3 years, 2 months ago) by maxv
Branches: MAIN
CVS tags: HEAD
Add a KASLR howto. Not much to say, but it needs to be officially said
somewhere. I'll perhaps add a nude or two to enlighten if there is some
confusion.

    1: [[!meta title="Using KASLR"]]
    2: 
    3: NetBSD supports Kernel ASLR on x86 64bit CPUs (amd64), starting from
    4: NetBSD 9.0.
    5: 
    6: Installation
    7: ------------
    8: 
    9: Install the prekern:
   10: 
   11: [[!template id=programlisting text="""
   12: # cp /usr/mdec/prekern /
   13: """]]
   14: 
   15: Obtain a GENERIC_KASLR kernel. Such a kernel can be either downloaded from
   16: the NetBSD FTP server, for example on:
   17: 
   18: [[!template id=programlisting text="""
   19: http://nycdn.netbsd.org/pub/NetBSD-daily/HEAD/201808020450Z/amd64/binary/kernel/netbsd-GENERIC_KASLR.gz
   20: """]]
   21: 
   22: Or compiled from scratch, using:
   23: 
   24: [[!template id=programlisting text="""
   25: # cd /usr/src
   26: # ./build.sh kernel=GENERIC_KASLR
   27: """]]
   28: 
   29: Install this KASLR kernel:
   30: 
   31: [[!template id=programlisting text="""
   32: # cp /path/to/your/kernel /netbsd_kaslr
   33: """]]
   34: 
   35: Finally, add the following line in the `/boot.cfg` file:
   36: 
   37: [[!template id=filecontent name="/boot.cfg" text="""
   38: menu=Boot KASLR:rndseed /var/db/entropy-file;pkboot netbsd_kaslr
   39: """]]
   40: 
   41: Now the installation is complete.
   42: 
   43: Use
   44: ---
   45: 
   46: To use KASLR, just choose the "Boot KASLR" option in the menu at boot
   47: time. That's it!
   48: 
   49: Technical Resources
   50: -------------------
   51: 
   52: * NetBSD.org: [Kernel ASLR on amd64](http://blog.netbsd.org/tnf/entry/kernel_aslr_on_amd64)
   53: * NetBSD.org: [The strongest KASLR, ever?](http://blog.netbsd.org/tnf/entry/the_strongest_kaslr_ever)
   54: 

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