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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