Date: Thu, 23 Feb 2023 13:34:41 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=269780 Bug ID: 269780 Summary: O_RESOLVE_BENEATH succeeds on ".." on "/" Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: firstname.lastname@example.org Thanks for adding the O_RESOLVE_BENEATH flag . I do have one report of surprising behavior with it. It seems that opening ".." with a base fd referencing "/" succeeds. This is understandable, because ".." in the root directory refers to the root directory, and indeed it's not outside the base fd in that case. However, use cases for O_RESOLVE_BENEATH would be better served by having an open of ".." with a base fd of the root directory fail. If one has path strings coming from an untrusted source, one wouldn't want the source to be able to tell where the base is in the overall filesystem namespace. If opening ".." at the top level succeeds, that reveals that the base directory is in fact the root directory. For comparison, Linux's openat2's RESOLVE_BENEATH flag fails on ".." at the root. : https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248335 -- You are receiving this mail because: You are the assignee for the bug.