Signed-off-by: David Drysdale <drysdale@xxxxxxxxxx> --- man2/open.2 | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/man2/open.2 b/man2/open.2 index 475d9e405908..c3d080fb3bea 100644 --- a/man2/open.2 +++ b/man2/open.2 @@ -705,7 +705,7 @@ in a fully formed state (using as described above). .RE .IP -.B O_TMPFILE +.B O_TMPFILE " (since Linux 3.??)" requires support by the underlying filesystem; only a subset of Linux filesystems provide that support. In the initial implementation, support was provided in @@ -715,6 +715,31 @@ XFS support was added .\" commit ab29743117f9f4c22ac44c13c1647fb24fb2bafe in Linux 3.15. .TP +.B O_BENEATH +Ensure that the +.I pathname +is beneath the current working directory (for +.BR open (2)) +or the +.I dirfd +(for +.BR openat (2)). +If the +.I pathname +is absolute or contains a path component of "..", the +.BR open () +fails with the error +.BR EACCES. +This occurs even if ".." path component would not actually +escape the original directory; for example, a +.I pathname +of "subdir/../filename" would be rejected. +Path components that are symbolic links to absolute paths, or that are +relative paths containing a ".." component, will also cause the +.BR open () +operation to fail with the error +.BR EACCES. +.TP .B O_TRUNC If the file already exists and is a regular file and the access mode allows writing (i.e., is @@ -791,7 +816,11 @@ The requested access to the file is not allowed, or search permission is denied for one of the directories in the path prefix of .IR pathname , or the file did not exist yet and write access to the parent directory -is not allowed. +is not allowed, or the +.B O_BENEATH +flag was specified and the +.I pathname +was not beneath the relevant directory. (See also .BR path_resolution (7).) .TP -- 2.0.0.526.g5318336 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
