On 4/25/23 08:32, Roi Dayan via dev wrote: > From: Gavin Li <[email protected]> > > Linux kernel netlink module added NLA_F_NESTED flag checking for nested > netlink messages in 5.2. A nested message without the flag set will be > treated as malformated one. The check is optional and is controlled by > message policy. To avoid this, add NLA_F_NESTED explicitly for all > nested netlink messages. > > Signed-off-by: Gavin Li <[email protected]> > Reviewed-by: Roi Dayan <[email protected]> > --- > lib/netlink.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/netlink.c b/lib/netlink.c > index 6215282d6fbe..f128b63074f9 100644 > --- a/lib/netlink.c > +++ b/lib/netlink.c > @@ -519,7 +519,7 @@ size_t > nl_msg_start_nested(struct ofpbuf *msg, uint16_t type) > { > size_t offset = msg->size; > - nl_msg_put_unspec_uninit(msg, type, 0); > + nl_msg_put_unspec_uninit(msg, type | NLA_F_NESTED, 0);
Are you sure this is safe? IIRC, the NLA_F_NESTED checking is not enforced on legacy interfaces like the OVS family. And the OVS kernel module in not using netlink macros in various places for iteration or attribute checking, so it may misinterpret the extra bit as an unknown attribute. Best regards, Ilya Maximets. _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
