Christian Brauner <christian.brau...@canonical.com> writes: > On Wed, Feb 07, 2018 at 12:19:25PM +0100, Jiri Benc wrote: >> On Tue, 6 Feb 2018 14:19:02 +0100, Christian Brauner wrote: >> > +/* Verify that rtnetlink requests supporting network namespace ids >> > + * do not pass additional properties potentially referring to different >> > + * network namespaces. >> > + */ >> > +static int rtnl_ensure_unique_netns(struct nlattr *tb[], >> > + struct netlink_ext_ack *extack) >> > +{ >> > + /* Requests without network namespace ids have been able to specify >> > + * multiple properties referring to different network namespaces so >> > + * don't regress them. >> > + */ >> > + if (!tb[IFLA_IF_NETNSID]) >> > + return 0; >> >> I agree with Eric that we should enforce this also for the existing >> pid/fd attributes. > > Yes, I would prefer this too but in the Linux spirit of never regressing > userspace I was afraid that there might already be userspace > applications that stick a pid and an fd at the same time into an > rtnetlink request. If we are ok with potentially breaking them then we > should just go for it. It is definitely the cleaner solution.
Odds are low that anything does anything so silly. If we accidentally cause a regression then we fix it. Unless you have reason to suspect someone actually does something silly we should be good. Eric