Re: [PATCH 0/5]: Preventing abuse when passing file descriptors

[David Miller <davem@davemloft.net>]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Wed, 23 Apr 2014 14:24:47 -0700

> Andy Lutomirski when looking at the networking stack noticed that it is
> possible to trick privilged processes into calling write on a netlink
> socket and send netlink messages they did not intend.
> 
> In particular from time to time there are suid applications that will
> write to stdout or stderr without checking exactly what kind of file
> descriptors those are and can be tricked into acting as a limited form
> of suid cat.  In other conversations the magic string CVE-2014-0181 has
> been used to talk about this issue.
> 
> This patchset cleans things up a bit, adds some clean abstractions that
> when used prevent this kind of problem and then finally changes all of
> the handlers of netlink messages that I could find that call capable to
> use netlink_ns_capable or an appropriate wrapper.
> 
> The abstraction netlink_ns_capable verifies that the original creator of
> the netlink socket a message is sent from had the necessary capabilities
> as well as verifying that the current sender of a netlink packet has the
> necessary capabilities.
> 
> The idea is to prevent file descriptor passing of any form from
> resulting in a file descriptor that can do more than it can for the
> creator of the file descriptor.

Series applied, thanks Eric.