{"id":102964,"date":"2022-01-14T21:37:17","date_gmt":"2022-01-14T19:37:17","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/%d1%83%d1%8f%d0%b7%d0%b2%d0%b8%d0%bc%d0%be%d1%81%d1%82%d1%8c-%d0%b2-xfs-%d0%bf%d0%be%d0%b7%d0%b2%d0%be%d0%bb%d1%8f%d1%8e%d1%89%d0%b0%d1%8f-%d1%87%d0%b8%d1%82%d0%b0%d1%82%d1%8c-%d1%81%d1%8b%d1%80"},"modified":"2022-01-14T21:37:17","modified_gmt":"2022-01-14T19:37:17","slug":"%d1%83%d1%8f%d0%b7%d0%b2%d0%b8%d0%bc%d0%be%d1%81%d1%82%d1%8c-%d0%b2-xfs-%d0%bf%d0%be%d0%b7%d0%b2%d0%be%d0%bb%d1%8f%d1%8e%d1%89%d0%b0%d1%8f-%d1%87%d0%b8%d1%82%d0%b0%d1%82%d1%8c-%d1%81%d1%8b%d1%80","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/news\/%d1%83%d1%8f%d0%b7%d0%b2%d0%b8%d0%bc%d0%be%d1%81%d1%82%d1%8c-%d0%b2-xfs-%d0%bf%d0%be%d0%b7%d0%b2%d0%be%d0%bb%d1%8f%d1%8e%d1%89%d0%b0%d1%8f-%d1%87%d0%b8%d1%82%d0%b0%d1%82%d1%8c-%d1%81%d1%8b%d1%80","title":{"rendered":"Zranite\u013enos\u0165 v XFS, ktor\u00e1 umo\u017e\u0148uje \u010d\u00edta\u0165 surov\u00e9 \u00fadaje blokov\u00e9ho zariadenia","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

V k\u00f3de s\u00faborov\u00e9ho syst\u00e9mu XFS bola zisten\u00e1 zranite\u013enos\u0165 (CVE-2021-4155), ktor\u00e1 umo\u017e\u0148uje lok\u00e1lnemu neopr\u00e1vnen\u00e9mu u\u017e\u00edvate\u013eovi priamo \u010d\u00edta\u0165 \u00fadaje nevyu\u017eit\u00fdch blokov z blokov\u00e9ho zariadenia. V\u0161etky v\u00fdznamn\u00e9 verzie jadra Linuxu star\u0161ie ako 5.16, obsahuj\u00face ovl\u00e1da\u010d XFS, s\u00fa touto probl\u00e9mom postihnut\u00e9. Oprava bola zahrnut\u00e1 vo verzii 5.16, ako aj v aktualiz\u00e1ci\u00e1ch jadier 5.15.14, 5.10.91, 5.4.171, 4.19.225 at\u010f. Stav vytv\u00e1rania aktualiz\u00e1ci\u00ed s odstr\u00e1nen\u00edm probl\u00e9mu v distrib\u00faci\u00e1ch je mo\u017en\u00e9 sledova\u0165 na t\u00fdchto str\u00e1nkach: Debian, RHEL, SUSE, Fedora, Ubuntu, Arch. <\/p>\n

Zranite\u013enos\u0165 je sp\u00f4soben\u00e1 nespr\u00e1vnym spr\u00e1van\u00edm dvoch \u0161pecifick\u00fdch pre XFS ioctl(XFS_IOC_ALLOCSP) a ioctl(XFS_IOC_FREESP), ktor\u00e9 s\u00fa funk\u010dn\u00fdm ekvivalentom v\u0161eobecn\u00e9ho syst\u00e9mov\u00e9ho volania fallocate(). Pri zvy\u0161ovan\u00ed ve\u013ekosti s\u00faboru, ktor\u00fd nie je zarovnan\u00fd na ve\u013ekos\u0165 bloku, ioctl XFS_IOC_ALLOCSP\/XFS_IOC_FREESP nevyma\u017e\u00fa koncov\u00e9 bajty do nasleduj\u00facej hranice bloku. T\u00fdmto sp\u00f4sobom m\u00f4\u017ee \u00fato\u010dn\u00edk na XFS so \u0161tandardnou ve\u013ekos\u0165ou bloku 4096 bajtov pre\u010d\u00edta\u0165 a\u017e 4095 bajtov predch\u00e1dzaj\u00facich zap\u00edsan\u00fdch \u00fadajov z ka\u017ed\u00e9ho bloku. V uveden\u00fdch oblastiach m\u00f4\u017eu by\u0165 ulo\u017een\u00e9 \u00fadaje odstr\u00e1nen\u00fdch s\u00faborov, defragmentovan\u00fdch s\u00faborov, ako aj s\u00faborov s deduplikovan\u00fdmi blokmi. <\/p>\n

Overi\u0165 svoju s\u00fastavu na pr\u00edtomnos\u0165 probl\u00e9mu je mo\u017en\u00e9 pomocou jednoduch\u00e9ho prototypu exploit\u00e1cie. Ak po vykonan\u00ed navrhnutej sekvencie pr\u00edkazov bude mo\u017en\u00e9 pre\u010d\u00edta\u0165 text Shakespeara, ovl\u00e1da\u010d FS je zranite\u013en\u00fd. Po\u010diato\u010dn\u00e1 mont\u00e1\u017e oddielu XFS na demon\u0161tr\u00e1ciu vy\u017eaduje pr\u00e1va superu\u017e\u00edvate\u013ea. <\/p>\n

Ke\u010f\u017ee ioctl(XFS_IOC_ALLOCSP) a ioctl(XFS_IOC_FREESP) sa funk\u010dne takmer nel\u00ed\u0161ia od \u0161tandardn\u00e9ho fallocate(), pri\u010dom ich jedin\u00fdm rozdielom je \u00fanik \u00fadajov, ich existencia p\u00f4sob\u00ed ako zadn\u00e9 dvierka. Napriek v\u0161eobecnej politike \u2013 nezasahova\u0165 do existuj\u00facich rozhran\u00ed v jadre \u2013 bolo na n\u00e1vrh Linusa prijat\u00e9 rozhodnutie \u00faplne odstr\u00e1ni\u0165 tieto ioctl v nasleduj\u00facej verzii.
\n
Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0412 \u043a\u043e\u0434\u0435 \u0444\u0430\u0439\u043b\u043e\u0432\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b XFS \u043e\u0431\u043d\u0430\u0440\u0443\u0436\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2021-4155), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u043c\u0443 \u043d\u0435\u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u0447\u0438\u0442\u0430\u0442\u044c \u0434\u0430\u043d\u043d\u044b\u0435 \u043d\u0435\u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0431\u043b\u043e\u043a\u043e\u0432 \u043d\u0430\u043f\u0440\u044f\u043c\u0443\u044e \u0441 \u0431\u043b\u043e\u0447\u043d\u043e\u0433\u043e \u0443\u0441\u0442\u0440\u043e\u0439\u0441\u0442\u0432\u0430. \u0412\u0441\u0435 \u0437\u043d\u0430\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u044b\u0435 \u0432\u0435\u0440\u0441\u0438\u0438 \u044f\u0434\u0440\u0430 Linux \u0441\u0442\u0430\u0440\u0448\u0435 5.16, \u0441\u043e\u0434\u0435\u0440\u0436\u0430\u0449\u0438\u0435 \u0434\u0440\u0430\u0439\u0432\u0435\u0440 XFS, \u043f\u043e\u0434\u0432\u0435\u0440\u0436\u0435\u043d\u044b \u044d\u0442\u043e\u0439 \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0435. \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 \u0432\u043e\u0448\u043b\u043e \u0432 \u0432\u0435\u0440\u0441\u0438\u044e 5.16, \u0430 \u0442\u0430\u043a\u0436\u0435 \u0432 \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f \u044f\u0434\u0435\u0440 5.15.14, 5.10.91, 5.4.171, 4.19.225 \u0438 \u0442.\u0434. \u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0444\u043e\u0440\u043c\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0441 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0435\u043c \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u044b […]<\/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":[702],"tags":[],"class_list":["post-102964","post","type-post","status-publish","format-standard","hentry","category-news"],"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\udd47Zranite\u013enos\u0165 v XFS, ktor\u00e1 umo\u017e\u0148uje \u010d\u00edta\u0165 surov\u00e9 \u00fadaje blokov\u00e9ho zariadenia | ProHoster","description":"V k\u00f3de s\u00faborov\u00e9ho syst\u00e9mu XFS bola zisten\u00e1 zranite\u013enos\u0165 (CVE-2021-4155), ktor\u00e1 umo\u017e\u0148uje lok\u00e1lnemu neopr\u00e1vnen\u00e9mu u\u017e\u00edvate\u013eovi priamo \u010d\u00edta\u0165 \u00fadaje nevyu\u017eit\u00fdch blokov z blokov\u00e9ho zariadenia.","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/news\/%d1%83%d1%8f%d0%b7%d0%b2%d0%b8%d0%bc%d0%be%d1%81%d1%82%d1%8c-%d0%b2-xfs-%d0%bf%d0%be%d0%b7%d0%b2%d0%be%d0%bb%d1%8f%d1%8e%d1%89%d0%b0%d1%8f-%d1%87%d0%b8%d1%82%d0%b0%d1%82%d1%8c-%d1%81%d1%8b%d1%80","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sk_SK","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\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 XFS, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0447\u0438\u0442\u0430\u0442\u044c \u0441\u044b\u0440\u044b\u0435 \u0434\u0430\u043d\u043d\u044b\u0435 \u0431\u043b\u043e\u0447\u043d\u043e\u0433\u043e \u0443\u0441\u0442\u0440\u043e\u0439\u0441\u0442\u0432\u0430 | ProHoster","og:description":"\u0412 \u043a\u043e\u0434\u0435 \u0444\u0430\u0439\u043b\u043e\u0432\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b XFS \u043e\u0431\u043d\u0430\u0440\u0443\u0436\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2021-4155), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u043c\u0443 \u043d\u0435\u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u0447\u0438\u0442\u0430\u0442\u044c \u0434\u0430\u043d\u043d\u044b\u0435 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