{"id":305,"date":"2010-02-18T11:15:41","date_gmt":"2010-02-18T19:15:41","guid":{"rendered":"http:\/\/www.outflux.net\/blog\/?p=305"},"modified":"2010-02-19T11:45:21","modified_gmt":"2010-02-19T19:45:21","slug":"data-mining-for-nx-bit","status":"publish","type":"post","link":"https:\/\/outflux.net\/blog\/archives\/2010\/02\/18\/data-mining-for-nx-bit\/","title":{"rendered":"data mining for NX bit"},"content":{"rendered":"<p>9% of Ubuntu systems that were used to report bugs that included their <code>\/proc\/cpuinfo<\/code> file need to fix their BIOS settings to <a href=\"http:\/\/www.outflux.net\/blog\/archives\/2008\/11\/21\/make-your-bios-love-security\/\">gain the NX bit<\/a>.<\/p>\n<p><a href=\"http:\/\/bazaar.launchpad.net\/~kees\/%2Bjunk\/cpu-checker\/annotate\/head%3A\/check-bios-nx\">Check<\/a> for yourself.  (Run it with <code>--verbose<\/code> for useful details.)<\/p>\n<p>Out of 7511 Ubuntu bugs <a href=\"http:\/\/www.murraytwins.com\/blog\">Brian Murray<\/a> collected for me that included <code>\/proc\/cpuinfo<\/code> files, there were 7270 unique contents (which surprised me &#8212; I was expecting this to be much lower).<\/p>\n<ul>\n<li>5 (0.07%) were non-x86.<\/li>\n<li>1 (0.02%) had corrupted contents (likely due to a search\/replace in apport gone awry).<\/li>\n<li>5670 (77.99%) had NX (this also surprised me &#8212; I was not expecting it to be so high).<\/li>\n<li>337 (4.64%) lacked PAE, and so cannot have NX (I didn&#8217;t expect this to be so low; Ubuntu bug reporters must have relatively recent hardware overall).<\/li>\n<li>595 (8.18%) had PAE and correctly lacked NX (I didn&#8217;t expect this to be so high &#8212; PAE without NX is a bit more common than I&#8217;d hoped; hopefully these systems are running 32bit kernels to at least get the partial NX emulation).<\/li>\n<li>662 (9.1%) had PAE but incorrectly lacked NX.<\/li>\n<\/ul>\n<p>It&#8217;s this last group of systems I&#8217;m hoping to get fixed through <a href=\"https:\/\/wiki.ubuntu.com\/Security\/CPUFeatures\">education<\/a>.<\/p>\n<p style='text-align:left'>&copy; 2010, <a href=\"https:\/\/outflux.net\/blog\/\">Kees Cook<\/a>. This work is licensed under a <a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">Creative Commons Attribution-ShareAlike 4.0 License<\/a>.<br \/><a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\"><img decoding=\"async\" alt=\"CC BY-SA 4.0\" style=\"border-width:0\" src=\"https:\/\/i.creativecommons.org\/l\/by-sa\/4.0\/88x31.png\" \/><\/a> <\/p>\n","protected":false},"excerpt":{"rendered":"<p>9% of Ubuntu systems that were used to report bugs that included their \/proc\/cpuinfo file need to fix their BIOS settings to gain the NX bit. Check for yourself. (Run it with &#8211;verbose for useful details.) Out of 7511 Ubuntu bugs Brian Murray collected for me that included \/proc\/cpuinfo files, there were 7270 unique contents [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,18,6,14,19],"tags":[],"_links":{"self":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts\/305"}],"collection":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/comments?post=305"}],"version-history":[{"count":6,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts\/305\/revisions"}],"predecessor-version":[{"id":310,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts\/305\/revisions\/310"}],"wp:attachment":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/media?parent=305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/categories?post=305"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/tags?post=305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}