{"id":1203146,"date":"2023-11-15T08:58:04","date_gmt":"2023-11-15T13:58:04","guid":{"rendered":"https:\/\/www.prime-wow.com\/?p=1203146"},"modified":"2023-11-15T08:58:04","modified_gmt":"2023-11-15T13:58:04","slug":"intels-redundant-prefix-issue","status":"publish","type":"post","link":"https:\/\/www.prime-wow.com\/?p=1203146","title":{"rendered":"Intel&#039;s &quot;redundant prefix issue&quot;"},"content":{"rendered":"<p>Tavis Ormandy has <a href=\"https:\/\/lock.cmpxchg8b.com\/reptar.html\">described a bug<\/a><br \/>\nin some Intel CPUs that can lead to a crash (or worse):\n<\/p>\n<\/p>\n<blockquote class=\"bq\"><p>\n\tWe believe this bug causes the frontend to miscalculate the size of<br \/>\n\tthe movsb instruction, causing subsequent entries in the ROB [reorder buffer] to be<br \/>\n\tassociated with incorrect addresses. When this happens, the CPU<br \/>\n\tenters a confused state that causes the instruction pointer to be<br \/>\n\tmiscalculated.<\/p>\n<p>\n\tThe machine can eventually recover from this state, perhaps with<br \/>\n\tincorrect intermediate results, but becoming internally consistent<br \/>\n\tagain. However, if we cause multiple SMT or SMP cores to enter the<br \/>\n\tstate simultaneously, we can cause enough microarchitectural state<br \/>\n\tcorruption to force a machine check.\n<\/p>\n<\/blockquote>\n<p>\nIntel has <a href=\"https:\/\/lwn.net\/ml\/oss-security\/ae728a21-91d5-463d-9f54-44186a01253d@intel.com\/\">released<br \/>\na microcode update<\/a> to address the issue.&#013;<br \/>\n&#013;<br \/>\nSource: LWN.net &#8211; <a href=\"https:\/\/lwn.net\/Articles\/951500\/\" target=\"_blank\" rel=\"noopener\">Intel&#8217;s &#8220;redundant prefix issue&#8221;<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tavis Ormandy has described a bug in some Intel CPUs that can lead to a crash (or worse): We believe this bug causes the frontend to miscalculate the size of the movsb instruction, causing subsequent entries in the ROB [reorder &hellip; <a href=\"https:\/\/www.prime-wow.com\/?p=1203146\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[72],"tags":[75],"class_list":["post-1203146","post","type-post","status-publish","format-standard","hentry","category-linux","tag-linux"],"_links":{"self":[{"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=\/wp\/v2\/posts\/1203146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1203146"}],"version-history":[{"count":0,"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=\/wp\/v2\/posts\/1203146\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1203146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1203146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.prime-wow.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1203146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}