https://bugzilla.redhat.com/show_bug.cgi?id=1586295
--- Comment #12 from Pavel Valena <pval...@redhat.com> --- (In reply to Jun Aruga from comment #10) > How about using mkstemp instead of mktemp? Though I am not confident for > that? or asking security guys? > > https://www.owasp.org/index.php/Insecure_Temporary_File > > Finally, mkstemp() is a reasonably safe way to create temporary files. In case you consider the implementation insecure, I think it's imperative to contact upstream and solve the issue with them. Fedora is no such place and in the end this needs to be resolved upstream anyway. > Are you sure? > It seems that the method "atomic_write_cache_file" which mktemp is called in > is expecting as a attomic. > But seeing the actual logic, I think the logic [2] is not related to the > called method atomic_write_cache_file. As you know, Mutex itself is used for > native thread. But it does not guarantee atomic access if lock is not used. > It depends on the implementation. Yes, like I wrote the mutex is used on Ruby level, not on C level. Whether that's secure or not is not for me to decide. However, there are two more conditions that'd have to be met for this to be a successfull attack, like I wrote already: > Furthermore, reading CAPEC[3], as suggested by rpmlint, none of the Attack > Prerequisites are not met AFAICT. > [3] http://capec.mitre.org/data/definitions/29.html ________________ > For example it seems that when below logic is called several times at same > timing, it does not guarantee the atomic access. > > ``` > irb(main):001:0> require 'bootsnap' > irb(main):006:0> Bootsnap.setup(cache_dir: '/tmp/foo', autoload_paths_cache: > false) > => :load_file > ``` Disregarding the attack vector, for the sake of the argument - Actually, I think it should be safe. Because when you use native Ruby Threads (like in a rails app), Bootsnap runs `@mutex.synchronize { ... }` everywhere[*] and the requests should not collide. [*] https://github.com/Shopify/bootsnap/blob/684acfd9b8c1298a026dd6b9c2ffeb173d11e949/lib/bootsnap/load_path_cache/cache.rb#L11 -- You are receiving this mail because: You are on the CC list for the bug. You are always notified about changes to this product and component _______________________________________________ package-review mailing list -- package-review@lists.fedoraproject.org To unsubscribe send an email to package-review-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/package-review@lists.fedoraproject.org/message/UWSFG3VO2HO6MQ6EQMXQS2MGQT2OHGJ6/
