A empresa Google analisou a efic\u00e1cia do uso no c\u00f3digo em C++ do tipo MiraclePtr (raw_ptr) em vez de ponteiros comuns para prevenir vulnerabilidades causadas por acessos a \u00e1reas de mem\u00f3ria j\u00e1 liberadas (use-after-free). O MiraclePtr fornece uma camada sobre os ponteiros, realizando verifica\u00e7\u00f5es adicionais e encerrando a execu\u00e7\u00e3o em caso de detec\u00e7\u00e3o de acessos a \u00e1reas de mem\u00f3ria liberadas. O suporte ao MiraclePtr foi habilitado por padr\u00e3o nas plataformas Windows e Android em maio de 2022 (no Chrome 102), e nas plataformas ChromeOS, Linux e macOS em junho de 2023. A prote\u00e7\u00e3o baseada em MiraclePtr no Chrome \u00e9 aplicada a todos os processos, exceto ao processo respons\u00e1vel pela renderiza\u00e7\u00e3o (renderer). <\/p>\n
Ap\u00f3s estudar a din\u00e2mica de envio de relat\u00f3rios de vulnerabilidades e encerramentos inesperados, bem como analisar incidentes de seguran\u00e7a e resultados de testes de fuzzing, chegou-se \u00e0 conclus\u00e3o de que a implementa\u00e7\u00e3o do MiraclePtr forneceu prote\u00e7\u00e3o contra 57% das vulnerabilidades do tipo use-after-free, gra\u00e7as \u00e0 migra\u00e7\u00e3o para o uso do MiraclePtr em campos de classes e par\u00e2metros de chamadas de retorno. Al\u00e9m disso, menciona-se que 5 das 6 vulnerabilidades cr\u00edticas identificadas no ano passado na vers\u00e3o est\u00e1vel do Chrome foram reconhecidas por meio do estudo dos relatos de encerramentos inesperados relacionados ao uso do MiraclePtr. <\/p>\n
O custo da aplica\u00e7\u00e3o do MiraclePtr \u00e9 o aumento no consumo de mem\u00f3ria, pois os ponteiros requerem armazenamento adicional de 4 bytes para o contador de refer\u00eancias. O consumo de mem\u00f3ria do processo principal do navegador ao usar o MiraclePtr aumenta em 5,5-8% nas compila\u00e7\u00f5es para sistemas desktop e em 2% na vers\u00e3o para Android. O aumento m\u00e9dio de consumo para todos os processos \u00e9 estimado entre 1-3%. Al\u00e9m disso, ao utilizar o MiraclePtr, foram observadas regress\u00f5es isoladas que levam a uma diminui\u00e7\u00e3o no desempenho, mas n\u00e3o est\u00e3o relacionadas a m\u00e9tricas-chave, como tempo de carregamento e renderiza\u00e7\u00e3o da p\u00e1gina. Das regress\u00f5es identificadas, destaca-se um atraso de 1,5% na primeira entrada no Chrome OS, uma desacelera\u00e7\u00e3o de 1,5% na abertura de abas na plataforma Android, bem como um aumento na probabilidade de atraso na entrada devido \u00e0 concorr\u00eancia no thread principal (aumento na probabilidade em 10% no percentil 99). \u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Google \u043f\u0440\u043e\u0430\u043d\u0430\u043b\u0438\u0437\u0438\u0440\u043e\u0432\u0430\u043b\u0430 \u044d\u0444\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u043e\u0441\u0442\u044c \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0432 \u043a\u043e\u0434\u0435 \u043d\u0430 \u044f\u0437\u044b\u043a\u0435 \u0421++ \u0442\u0438\u043f\u0430 MiraclePtr (raw_ptr<T>) \u0432\u043c\u0435\u0441\u0442\u043e \u043e\u0431\u044b\u0447\u043d\u044b\u0445 \u0443\u043a\u0430\u0437\u0430\u0442\u0435\u043b\u0435\u0439 \u0434\u043b\u044f \u0437\u0430\u0449\u0438\u0442\u044b \u043e\u0442 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0435\u0439, \u0432\u044b\u0437\u0432\u0430\u043d\u043d\u044b\u0445 \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435\u043c \u043a \u0443\u0436\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0451\u043d\u043d\u044b\u043c \u043e\u0431\u043b\u0430\u0441\u0442\u044f\u043c \u043f\u0430\u043c\u044f\u0442\u0438 (use-after-free). MiraclePtr \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 \u043e\u0431\u0432\u044f\u0437\u043a\u0443 \u043d\u0430\u0434 \u0443\u043a\u0430\u0437\u0430\u0442\u0435\u043b\u044f\u043c\u0438, \u0432\u044b\u043f\u043e\u043b\u043d\u044f\u044e\u0449\u0443\u044e \u0434\u043e\u043f\u043e\u043b\u043d\u0438\u0442\u0435\u043b\u044c\u043d\u044b\u0435 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0438 \u0438 \u0430\u0432\u0430\u0440\u0438\u0439\u043d\u043e \u0437\u0430\u0432\u0435\u0440\u0448\u0430\u044e\u0449\u0443\u044e \u0440\u0430\u0431\u043e\u0442\u0443 \u0432 \u0441\u043b\u0443\u0447\u0430\u0435 \u043e\u0431\u043d\u0430\u0440\u0443\u0436\u0435\u043d\u0438\u044f \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u044f \u043a \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0451\u043d\u043d\u044b\u043c \u043e\u0431\u043b\u0430\u0441\u0442\u044f\u043c \u043f\u0430\u043c\u044f\u0442\u0438. \u041f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0430 MiraclePtr \u0431\u044b\u043b\u0430 \u0432\u043a\u043b\u044e\u0447\u0435\u043d\u0430 \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e \u043d\u0430 […]<\/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-113077","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\udd47 Avalia\u00e7\u00e3o da efic\u00e1cia do MiraclePtr na preven\u00e7\u00e3o de vulnerabilidades no Chrome | ProHoster","description":"A empresa Google analisou a efic\u00e1cia do uso do tipo MiraclePtr (raw_ptr) em c\u00f3digo C++ em vez de ponteiros comuns para prevenir 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\u043f\u0440\u0435\u0434\u043e\u0442\u0432\u0440\u0430\u0449\u0435\u043d\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0435\u0439 \u0432 Chrome | ProHoster","og:description":"\u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Google \u043f\u0440\u043e\u0430\u043d\u0430\u043b\u0438\u0437\u0438\u0440\u043e\u0432\u0430\u043b\u0430 \u044d\u0444\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u043e\u0441\u0442\u044c \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0432 \u043a\u043e\u0434\u0435 \u043d\u0430 \u044f\u0437\u044b\u043a\u0435 \u0421++ \u0442\u0438\u043f\u0430 MiraclePtr (raw_ptr) \u0432\u043c\u0435\u0441\u0442\u043e \u043e\u0431\u044b\u0447\u043d\u044b\u0445 \u0443\u043a\u0430\u0437\u0430\u0442\u0435\u043b\u0435\u0439 \u0434\u043b\u044f \u0437\u0430\u0449\u0438\u0442\u044b \u043e\u0442 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0435\u0439, \u0432\u044b\u0437\u0432\u0430\u043d\u043d\u044b\u0445 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\u043e\u0431\u043b\u0430\u0441\u0442\u044f\u043c.","og:url":"https:\/\/prohoster.info\/pt\/blog\/news\/oczenka-effektivnosti-primeneniya-miracleptr-dlya-predotvrashheniya-uyazvimostej-v-chrome","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":"2024-01-23T15:28:02+00:00","article:modified_time":"2024-01-23T15:28:02+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":[],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/113077","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/comments?post=113077"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/113077\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/media?parent=113077"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/categories?post=113077"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/tags?post=113077"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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Fonte: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"