{"id":397,"date":"2016-08-02T12:48:14","date_gmt":"2016-08-02T10:48:14","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=397"},"modified":"2016-09-07T14:36:00","modified_gmt":"2016-09-07T12:36:00","slug":"syslog-ng-null-pointer-dereference-in-report_syntax_error-cfg-parser-c","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2016\/08\/02\/syslog-ng-null-pointer-dereference-in-report_syntax_error-cfg-parser-c\/","title":{"rendered":"syslog-ng: NULL pointer dereference in report_syntax_error (cfg-parser.c)"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"https:\/\/www.balabit.com\/network-security\/syslog-ng\">syslog-ng<\/a> is an enhanced log daemon, supporting a wide range of input and output methods: syslog, unstructured text, message queues, databases (SQL and NoSQL alike) and more.<\/p>\n<p>A crafted config crashes the process because of a NULL pointer access.<\/p>\n<p>The complete ASan output:<\/p>\n<pre><font size=\"2\">syslog-ng -s -f $file\r\nASAN:SIGSEGV\r\n=================================================================\r\n==8120==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x7efcda07e49d bp 0x7ffd06c89ef0 sp 0x7ffd06c89980 T0)\r\n    #0 0x7efcda07e49c in report_syntax_error \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg-parser.c:250:3\r\n    #1 0x7efcda1adc91 in pragma_parse \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/pragma-grammar.c:3003:9\r\n    #2 0x7efcda0759ba in cfg_parser_parse \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/.\/lib\/cfg-parser.h:83:14\r\n    #3 0x7efcda0759ba in cfg_lexer_lex \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg-lexer.c:822\r\n    #4 0x7efcda19b2a7 in main_parse \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg-grammar.c:3070:16\r\n    #5 0x7efcda06ac8b in cfg_parser_parse \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/.\/lib\/cfg-parser.h:83:14\r\n    #6 0x7efcda06ac8b in cfg_run_parser \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg.c:420\r\n    #7 0x7efcda06b920 in cfg_read_config \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg.c:492:13\r\n    #8 0x7efcda101975 in main_loop_read_and_init_config \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/mainloop.c:450:8\r\n    #9 0x4b8eba in main \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/syslog-ng\/main.c:258:8\r\n    #10 0x7efcd8feeaa4 in __libc_start_main (\/lib64\/libc.so.6+0x21aa4)\r\n    #11 0x4b7cdc in _start (\/usr\/sbin\/syslog-ng+0x4b7cdc)\r\n\r\nAddressSanitizer can not provide additional info.\r\nSUMMARY: AddressSanitizer: SEGV \/tmp\/portage\/app-admin\/syslog-ng-3.7.3\/work\/syslog-ng-3.7.3\/lib\/cfg-parser.c:250 report_syntax_error\r\n==8120==ABORTING\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n3.7.3<\/p>\n<p><strong>Fixed version:<\/strong><br \/>\nN\/A<\/p>\n<p><strong>Commit fix:<\/strong><br \/>\n<a href=\"https:\/\/github.com\/balabit\/syslog-ng\/pull\/1067\/commits\/a460630d310014fde914d86f6024674653557ec1\">https:\/\/github.com\/balabit\/syslog-ng\/pull\/1067\/commits\/a460630d310014fde914d86f6024674653557ec1<\/a><\/p>\n<p><strong>Credit:<\/strong><br \/>\nThis bug was discovered by Agostino Sarubbo of Gentoo.<\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2016-05-17: bug discovered<br \/>\n2016-05-17: bug reported to upstream<br \/>\n2016-05-27: upstream released a fix<br \/>\n2016-08-02: blog post about the issue<\/p>\n<p><strong>Note:<\/strong><br \/>\nThis bug was found with <a href=\"http:\/\/lcamtuf.coredump.cx\/afl\">American Fuzzy Lop<\/a>.<\/p>\n<p><strong>Permalink:<\/strong><\/p>\n<blockquote data-secret=\"7OPnoePsuD\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2016\/08\/02\/syslog-ng-null-pointer-dereference-in-report_syntax_error-cfg-parser-c\/\">syslog-ng: NULL pointer dereference in report_syntax_error (cfg-parser.c)<\/a><\/p><\/blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" src=\"http:\/\/blogs.gentoo.org\/ago\/2016\/08\/02\/syslog-ng-null-pointer-dereference-in-report_syntax_error-cfg-parser-c\/embed\/#?secret=7OPnoePsuD\" data-secret=\"7OPnoePsuD\" width=\"600\" height=\"338\" title=\"&#8220;syslog-ng: NULL pointer dereference in report_syntax_error (cfg-parser.c)&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: syslog-ng is an enhanced log daemon, supporting a wide range of input and output methods: syslog, unstructured text, message queues, databases (SQL and NoSQL alike) and more. A crafted config crashes the process because of a NULL pointer access. &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2016\/08\/02\/syslog-ng-null-pointer-dereference-in-report_syntax_error-cfg-parser-c\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":140,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true},"categories":[12,10],"tags":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2EaBc-6p","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/397"}],"collection":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/users\/140"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/comments?post=397"}],"version-history":[{"count":2,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/397\/revisions"}],"predecessor-version":[{"id":399,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/397\/revisions\/399"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}