{"id":41110,"date":"2020-02-05T21:30:57","date_gmt":"2020-02-05T18:30:57","guid":{"rendered":"https:\/\/prohoster.info\/blog\/blog_prohoster\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot"},"modified":"2020-02-05T21:30:57","modified_gmt":"2020-02-05T18:30:57","slug":"metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","title":{"rendered":"Metody deaktivace ochrany Lockdown v Ubuntu pro vzd\u00e1len\u00e9 obch\u00e1zen\u00ed UEFI Secure Boot","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Andrej Konovalov z firmy Google vydal<\/a><\/noindex> metoda vzd\u00e1len\u00e9ho vypnut\u00ed ochrany Lockdown<\/a><\/noindex>, nab\u00edzen\u00e9 v bal\u00ed\u010dku s j\u00e1drem Linuxu dod\u00e1van\u00e9m v Ubuntu (teoreticky navrhovan\u00e9 metody mus\u00ed<\/a><\/noindex> fungovat s j\u00e1drem Fedora a dal\u0161\u00edch distribuc\u00ed, ale nebyly testov\u00e1ny). <\/p>\n

Lockdown omezuje p\u0159\u00edstup u\u017eivatele root k j\u00e1dru a blokuje obch\u00e1zen\u00ed UEFI Secure Boot. Nap\u0159\u00edklad v re\u017eimu lockdown je omezen p\u0159\u00edstup k \/dev\/mem, \/dev\/kmem, \/dev\/port, \/proc\/kcore, debugfs, ladic\u00edm re\u017eimu kprobes, mmiotrace, tracefs, BPF, PCMCIA CIS (Card Information Structure), n\u011bkter\u00fdm rozhran\u00edm ACPI a CPU MSR registr\u016fm, blokov\u00e1ny jsou vol\u00e1n\u00ed kexec_file a kexec_load, zak\u00e1z\u00e1n je p\u0159echod do sp\u00e1nkov\u00e9ho re\u017eimu, omezeno je pou\u017e\u00edv\u00e1n\u00ed DMA pro PCI za\u0159\u00edzen\u00ed, zak\u00e1z\u00e1n je import k\u00f3du ACPI z EFI prom\u011bnn\u00fdch, manipulace s vstupn\u011b-v\u00fdstupn\u00edmi porty, v\u010detn\u011b zm\u011bny \u010d\u00edsla p\u0159eru\u0161en\u00ed a vstupn\u011b-v\u00fdstupn\u00edho portu pro s\u00e9riov\u00fd port.<\/p>\n

Mechanismus Lockdown byl ned\u00e1vno p\u0159id\u00e1n do j\u00e1dra Linuxu 5.4<\/a><\/noindex>, ale v j\u00e1drech dod\u00e1van\u00fdch v distribuc\u00edch je st\u00e1le implementov\u00e1n ve form\u011b patch\u016f nebo je dopln\u011bn patchemi. Jedn\u00edm z rozd\u00edl\u016f poskytovan\u00fdch v distribuc\u00edch p\u0159\u00eddavk\u016f od integrovan\u00e9 implementace v j\u00e1d\u0159e je mo\u017enost deaktivace poskytovan\u00e9 blokace p\u0159i fyzick\u00e9m p\u0159\u00edstupu k syst\u00e9mu. <\/p>\n

V Ubuntu a Fedo\u0159e je pro vypnut\u00ed Lockdown ur\u010dena kombinace kl\u00e1ves Alt+SysRq+X. P\u0159edpokl\u00e1d\u00e1 se, \u017ee kombinaci Alt+SysRq+X lze pou\u017e\u00edt pouze p\u0159i fyzick\u00e9m p\u0159\u00edstupu k za\u0159\u00edzen\u00ed, a v p\u0159\u00edpad\u011b vzd\u00e1len\u00e9ho hacknut\u00ed a z\u00edsk\u00e1n\u00ed p\u0159\u00edstupu root \u00fato\u010dn\u00edk nebude schopen Lockdown vypnout a nap\u0159\u00edklad na\u010d\u00edst do j\u00e1dra nezaru\u010den\u00fd digit\u00e1ln\u011b podepsan\u00fd modul s rootkitem. <\/p>\n

Andrej Konovalov uk\u00e1zal, \u017ee metody potvrzen\u00ed fyzick\u00e9 p\u0159\u00edtomnosti u\u017eivatele spojen\u00e9 s pou\u017e\u00edv\u00e1n\u00edm kl\u00e1vesnice jsou neefektivn\u00ed. Nejjednodu\u0161\u0161\u00edm zp\u016fsobem, jak deaktivovat Lockdown, by byla programov\u00e1 simulace<\/a><\/noindex> stisknut\u00ed Alt+SysRq+X p\u0159es \/dev\/uinput, ale tato mo\u017enost byla od po\u010d\u00e1tku blokov\u00e1na. P\u0159esto bylo mo\u017en\u00e9 odhalit alespo\u0148 dv\u011b dal\u0161\u00ed zp\u016fsoby, jak substituovat Alt+SysRq+X. <\/p>\n

Prvn\u00ed zp\u016fsob spo\u010d\u00edv\u00e1 v pou\u017eit\u00ed rozhran\u00ed «sysrq-trigger» — pro simulaci sta\u010d\u00ed povolit toto rozhran\u00ed zaps\u00e1n\u00edm «1» do \/proc\/sys\/kernel\/sysrq a pot\u00e9 zapsat «x» do \/proc\/sysrq-trigger. Uveden\u00e1 d\u00edra v zabezpe\u010den\u00ed odstran\u011bna<\/a><\/noindex> v prosincov\u00e9 aktualizaci j\u00e1dra Ubuntu a ve Fedo\u0159e 31. Je pozoruhodn\u00e9, \u017ee v\u00fdvoj\u00e1\u0159i, podobn\u011b jako v p\u0159\u00edpad\u011b \/dev\/uinput, zpo\u010d\u00e1tku se pokou\u0161eli<\/a><\/noindex> tento zp\u016fsob zablokovat, ale blokace nefungovala kv\u016fli chyb\u011b<\/a><\/noindex> v k\u00f3du.<\/p>\n

Druh\u00fd zp\u016fsob souvis\u00ed s emulac\u00ed kl\u00e1vesnice p\u0159es USB\/IP<\/a><\/noindex> a n\u00e1sledn\u00fdm odesl\u00e1n\u00edm sekvence Alt+SysRq+X z virtu\u00e1ln\u00ed kl\u00e1vesnice. V dod\u00e1van\u00e9m j\u00e1dru Ubuntu je USB\/IP ve v\u00fdchoz\u00edm nastaven\u00ed zapnuto (CONFIG_USBIP_VHCI_HCD=m a CONFIG_USBIP_CORE=m) a jsou poskytnuty pot\u0159ebn\u00e9 pro pr\u00e1ci certifikovan\u00e9 moduly usbip_core a vhci_hcd. \u00dato\u010dn\u00edk m\u016f\u017ee vytvo\u0159it<\/a><\/noindex> virtu\u00e1ln\u00ed USB za\u0159\u00edzen\u00ed, spu\u0161t\u011bn\u00edm<\/a><\/noindex> s\u00ed\u0165ov\u00e9ho zpracovatele na loopback rozhran\u00ed a p\u0159ipojen\u00edm ho jako vzd\u00e1len\u00e9 USB za\u0159\u00edzen\u00ed pomoc\u00ed USB\/IP. O uveden\u00e9 metod\u011b bylo informov\u00e1no<\/a><\/noindex> v\u00fdvoj\u00e1\u0159\u016fm Ubuntu, ale oprava zat\u00edm nebyla vyd\u00e1na.<\/p>\n

<\/a><\/noindex><\/p>\n

Zdroj: opennet.ru<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0410\u043d\u0434\u0440\u0435\u0439 \u041a\u043e\u043d\u043e\u0432\u0430\u043b\u043e\u0432 \u0438\u0437 \u043a\u043e\u043c\u043f\u0430\u043d\u0438\u0438 Google \u043e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043b \u0441\u043f\u043e\u0441\u043e\u0431 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b Lockdown, \u043f\u0440\u0435\u0434\u043b\u0430\u0433\u0430\u0435\u043c\u043e\u0439 \u0432 \u043f\u0430\u043a\u0435\u0442\u0435 \u0441 \u044f\u0434\u0440\u043e\u043c Linux, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 Ubuntu (\u0442\u0435\u043e\u0440\u0435\u0442\u0438\u0447\u0435\u0441\u043a\u0438 \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b \u0434\u043e\u043b\u0436\u043d\u044b \u0440\u0430\u0431\u043e\u0442\u0430\u0442\u044c \u0441 \u044f\u0434\u0440\u043e\u043c Fedora \u0438 \u0434\u0440\u0443\u0433\u0438\u0445 \u0434\u0438\u0441\u0442\u0440\u0438\u0431\u0443\u0442\u0438\u0432\u043e\u0432, \u043d\u043e \u043e\u043d\u0438 \u043d\u0435 \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u043d\u044b). Lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442 \u0434\u043e\u0441\u0442\u0443\u043f \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f root \u043a \u044f\u0434\u0440\u0443 \u0438 \u0431\u043b\u043e\u043a\u0438\u0440\u0443\u0435\u0442 \u043f\u0443\u0442\u0438 \u043e\u0431\u0445\u043e\u0434\u0430 UEFI Secure Boot. \u041d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \u0432 \u0440\u0435\u0436\u0438\u043c\u0435 lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u0434\u043e\u0441\u0442\u0443\u043f […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-41110","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Metody vypnut\u00ed ochrany Lockdown v Ubuntu pro vzd\u00e1len\u00e9 obch\u00e1zen\u00ed UEFI Secure Boot | ProHoster","description":"Andrej Konovalov z firmy Google publikoval zp\u016fsob vzd\u00e1len\u00e9ho vypnut\u00ed ochrany","canonical_url":"https:\/\/prohoster.info\/cs\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"cs_CZ","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u041c\u0435\u0442\u043e\u0434\u044b \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b Lockdown \u0432 Ubuntu \u0434\u043b\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0431\u0445\u043e\u0434\u0430 UEFI Secure Boot | ProHoster","og:description":"\u0410\u043d\u0434\u0440\u0435\u0439 \u041a\u043e\u043d\u043e\u0432\u0430\u043b\u043e\u0432 \u0438\u0437 \u043a\u043e\u043c\u043f\u0430\u043d\u0438\u0438 Google \u043e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043b \u0441\u043f\u043e\u0441\u043e\u0431 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b","og:url":"https:\/\/prohoster.info\/cs\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","og:image":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:secure_url":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:width":350,"og:image:height":350,"article:published_time":"2020-02-05T18:30:57+00:00","article:modified_time":"2020-02-05T18:30:57+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"41110","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":null,"schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"seo_analyzer_scan_date":null,"breadcrumb_settings":null,"limit_modified_date":false,"reviewed_by":null,"ai":null,"created":"2021-02-28 10:48:15","updated":"2022-09-28 13:36:48","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/41110","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/comments?post=41110"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/41110\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/media?parent=41110"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/categories?post=41110"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/tags?post=41110"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}