On linux you can use firejail if it's necessary (or a container if it's needed).
Re:Pledge and Unveil in OpenBSD [pdf]
by staticassertion on Sunday June 10, 2018 @02:17PM
(#17279398)
This doesn't address what they just said - dropping privileges incrementally. Firejail is just a whole process filter applied at process start.
brings me to the next question: are there linux equivalent ?
Re:Pledge and Unveil in OpenBSD [pdf]
by 2trill2spill on Sunday June 10, 2018 @12:39PM
(#17278875)
There's Capsicum for Linux[1]. Its a port of Capsicum[2] from FreeBSD to Linux. Capsicum was a joint project between the FreeBSD foundation, Cambridge and Google to create a hybrid capabilities framework. But Capsicum allows developers to do the same privilege dropping that pledge does. However Capsicum is more fine grained then pledge so its less easy to use. Also Capsicum for Linux is also out of tree currently.
[1]: http://www.capsicum-linux.org/ [2]: https://www.freebsd.org/cgi/man.cgi?capsicum(4)
Link #1 is neat for Linux users, but Google seems to have stopped updating Capsicum after v4.11 (which was released April 2017).
pledge() can also be found in over 85% of OpenBSD's base system.