Ben Pfaff <b...@ovn.org> writes: > On Mon, Jun 13, 2016 at 05:36:34PM -0400, Aaron Conole wrote: >> > If these limitations are unacceptable, I can see how we can use >> > chmod. After all, as you point out, it's probably better to do it >> > in OVS than in some script. >> >> I think fchmod and fchown may actually be the correct calls to have, and >> will refactor these chown/chmod utils functions as such, which (I >> believe) avoids the race as you describe.
I've done quite a bit of illuminating reading on the subject. The best I've seen is a usenix paper from 08[1] which describes a specific type of TOCTTOU mitigation that is still not 100% effective. This is a rather complicated subject. Whoops! > There are some pitfalls with fchmod() on Unix domain sockets, especially > on non-Linux systems. Please refer to bind_unix_socket() in > ... > I do not know whether the same pitfalls apply to fchown(). After much testing, it appears yes the same pitfalls apply. However, the downgrade with dpdk may not work correctly - I'm currently devising some test cases to sort this out. [1]: https://www.usenix.org/legacy/event/fast08/tech/full_papers/tsafrir/tsafrir_html/index.html Thanks both of you for your keen insights! -Aaron _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
