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        <title>BaSzErr - blog:2018:01:04</title>
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            <title>2017-01-04_-_postponed_fireworks</title>
            <link>https://baszerr.eu/doku.php?id=blog:2018:01:04:2017-01-04_-_postponed_fireworks</link>
            <description>
&lt;h1 class=&quot;sectionedit1&quot; id=&quot;postponed_fireworks&quot;&gt;2018-01-04 - postponed fireworks?&lt;/h1&gt;
&lt;div class=&quot;level1&quot;&gt;

&lt;p&gt;
&lt;a href=&quot;https://baszerr.eu/lib/exe/detail.php?id=blog%3A2018%3A01%3A04%3A2017-01-04_-_postponed_fireworks&amp;amp;media=blog:2018:01:04:spectre.png&quot; class=&quot;media&quot; title=&quot;blog:2018:01:04:spectre.png&quot;&gt;&lt;img src=&quot;https://baszerr.eu/lib/exe/fetch.php?w=300&amp;amp;tok=3e7e2e&amp;amp;media=blog:2018:01:04:spectre.png&quot; class=&quot;mediaright&quot; align=&quot;right&quot; loading=&quot;lazy&quot; title=&quot;spectre&quot; alt=&quot;spectre&quot; width=&quot;300&quot; /&gt;&lt;/a&gt;
&lt;a href=&quot;https://baszerr.eu/lib/exe/detail.php?id=blog%3A2018%3A01%3A04%3A2017-01-04_-_postponed_fireworks&amp;amp;media=blog:2018:01:04:meltdown.png&quot; class=&quot;media&quot; title=&quot;blog:2018:01:04:meltdown.png&quot;&gt;&lt;img src=&quot;https://baszerr.eu/lib/exe/fetch.php?w=200&amp;amp;tok=8378d4&amp;amp;media=blog:2018:01:04:meltdown.png&quot; class=&quot;mediaright&quot; align=&quot;right&quot; loading=&quot;lazy&quot; title=&quot;meltdown&quot; alt=&quot;meltdown&quot; width=&quot;200&quot; /&gt;&lt;/a&gt;
&lt;/p&gt;

&lt;p&gt;
looks like the real new year&amp;#039;s eve fireworks have been postponed to the January the 3rd – &lt;a href=&quot;https://meltdownattack.com&quot; class=&quot;urlextern&quot; title=&quot;https://meltdownattack.com&quot; rel=&quot;ugc nofollow&quot;&gt;two new security attacks on CPUs have just been released&lt;/a&gt;. yes – CPUs. the hardware part – not the software!
&lt;/p&gt;

&lt;p&gt;
looks like we&amp;#039;re having a side-channel attack here, that allows to leak information on the parts of the memory, normally inaccessible to the “attacking” process. the thing is ingenious… and terrifying in results.
&lt;/p&gt;

&lt;p&gt;
one of the variants is exploiting the fact, that speculative instruction execution can load memory regions into cache, even if the actual regions would not be normally accessible to the process. &lt;abbr title=&quot;Too long; didn&amp;#039;t read&quot;&gt;TL;DR&lt;/abbr&gt;. when processor “rollbacks” results of a branch misprediction, cached (prefetched) content remains, and this fact can be used to extract content of the original part, using side-channel and timing attacks.
&lt;/p&gt;

&lt;p&gt;
stay tuned for incoming patches, that are designed to minimize the impact… but hit performance, as each kernel-space ↔ user-space transition will now be associated with extra performance penalty. hopefully next generation of CPUs will not have the problem, and we can restore the performance “back to normal”.
&lt;/p&gt;

&lt;p&gt;
with &lt;a href=&quot;https://en.wikipedia.org/wiki/row hammer&quot; class=&quot;interwiki iw_wp&quot; title=&quot;https://en.wikipedia.org/wiki/row hammer&quot;&gt;row hammer&lt;/a&gt; in pair, the next PC shall have some new series of “patched” CPUs (so that kernels can be restored to faster variants) and &lt;a href=&quot;https://en.wikipedia.org/wiki/ECC memory&quot; class=&quot;interwiki iw_wp&quot; title=&quot;https://en.wikipedia.org/wiki/ECC memory&quot;&gt;ECC memory&lt;/a&gt;!
&lt;/p&gt;

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            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Tue, 15 Jun 2021 20:09:08 +0000</pubDate>
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