{"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\/pl\/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":"Vulnerability in XFS allowing reading raw data from block device","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

W kodzie systemu plik\u00f3w XFS wykryto luk\u0119 (CVE-2021-4155), kt\u00f3ra pozwala lokalnemu u\u017cytkownikowi bez przywilej\u00f3w na odczyt danych z nieu\u017cywanych blok\u00f3w bezpo\u015brednio z urz\u0105dzenia blokowego. Wszystkie istotne wersje j\u0105dra Linux powy\u017cej 5.16, zawieraj\u0105ce sterownik XFS, s\u0105 nara\u017cone na ten problem. Poprawka znalaz\u0142a si\u0119 w wersji 5.16, a tak\u017ce w aktualizacjach j\u0105der 5.15.14, 5.10.91, 5.4.171, 4.19.225 itd. Stan formowania aktualizacji z rozwi\u0105zaniem problemu w dystrybucjach mo\u017cna \u015bledzi\u0107 na tych stronach: Debian, RHEL, SUSE, Fedora, Ubuntu, Arch. <\/p>\n

Luka zosta\u0142a spowodowana niepoprawnym zachowaniem dw\u00f3ch specyficznych dla XFS ioctl(XFS_IOC_ALLOCSP) oraz ioctl(XFS_IOC_FREESP), kt\u00f3re s\u0105 funkcjonalnym odpowiednikiem og\u00f3lnosystemowego wywo\u0142ania fallocate(). Przy zwi\u0119kszaniu rozmiaru pliku, kt\u00f3ry nie jest wy\u015brodkowany na rozmiar bloku, ioctl XFS_IOC_ALLOCSP\/XFS_IOC_FREESP nie zeruj\u0105 bajt\u00f3w ko\u0144cowych do nast\u0119pnej granicy bloku. W ten spos\u00f3b na XFS o standardowym rozmiarze bloku 4096 bajt\u00f3w napastnik mo\u017ce odczyta\u0107 do 4095 bajt\u00f3w wcze\u015bniej zapisanych danych z ka\u017cdego bloku. W wskazanych obszarach mog\u0105 znajdowa\u0107 si\u0119 dane usuni\u0119tych plik\u00f3w, zdefragmentowanych plik\u00f3w, a tak\u017ce plik\u00f3w z deduplikowanymi blokami. <\/p>\n

Mo\u017cesz sprawdzi\u0107 sw\u00f3j system pod k\u0105tem problemu za pomoc\u0105 prostego prototypu exploita. Je\u015bli po wykonaniu sugerowanej sekwencji polece\u0144 uda si\u0119 odczyta\u0107 tekst Szekspira, to sterownik systemu plik\u00f3w jest podatny na ataki. Pocz\u0105tkowe zamontowanie partycji XFS w celach demonstracyjnych wymaga praw superu\u017cytkownika. <\/p>\n

Poniewa\u017c ioctl(XFS_IOC_ALLOCSP) i ioctl(XFS_IOC_FREESP) funkcjonalnie niemal nie r\u00f3\u017cni\u0105 si\u0119 od standardowego fallocate(), a ich jedyn\u0105 r\u00f3\u017cnic\u0105 jest wyciek danych, ich obecno\u015b\u0107 przypomina backdoora. Pomimo og\u00f3lnej polityki \u2013 nie zmienia\u0107 istniej\u0105cych interfejs\u00f3w w j\u0105drze \u2013 na wniosek Linusa podj\u0119to decyzj\u0119 o ca\u0142kowitym usuni\u0119ciu tych ioctl'i w nast\u0119pnej wersji.
\n
\u0179r\u00f3d\u0142o: 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\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\udd47Luka w XFS, pozwalaj\u0105ca na odczyt surowych danych z urz\u0105dzenia blokowego | ProHoster","description":"W kodzie systemu plik\u00f3w XFS wykryto luk\u0119 (CVE-2021-4155), kt\u00f3ra pozwala lokalnemu u\u017cytkownikowi bez przywilej\u00f3w na odczyt danych z nieu\u017cywanych blok\u00f3w bezpo\u015brednio z urz\u0105dzenia blokowego.","canonical_url":"https:\/\/prohoster.info\/pl\/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":"pl_PL","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 \u043d\u0435\u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0431\u043b\u043e\u043a\u043e\u0432 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