From: Ben Pfaff <redacted>
Date: Mon, 30 Jun 2014 15:35:04 -0700

netlink_dump() returns a negative errno value on error.  Until now,
netlink_recvmsg() directly recorded that negative value in sk->sk_err,
but that's wrong since sk_err takes positive errno values.  (This manifests
as userspace receiving a positive return value from the recv() system call,
falsely indicating success.)

This bug was introduced in the commit that started checking the
netlink_dump() return value, commit b44d211 (netlink: handle errors from
netlink_dump()).

Multithreaded Netlink dumps are one way to trigger this behavior in
practice, as described in the commit message for the userspace workaround
posted here:
    http://openvswitch.org/pipermail/dev/2014-June/042339.html

Signed-off-by: Ben Pfaff <redacted>

There's another place, later in this file, doing the same exact thing.

Please respin this patch, fixing that location too.

Thanks.