On Mon, 2018-01-15 at 15:48 +0100, Benjamin Beichler wrote: > > > + if (get_hwsim_data_ref_from_addr( > > > + nla_data(info->attrs[HWSIM_ATTR_PERM_ADDR]))) { > > > + pr_debug("mac80211_hwsim: perm MAC already in use\n"); > > > + return -EINVAL; > > > + } > > > > This is racy afaict - remove it and return a clash later when you fail > > to insert the new radio. > > Ehm yes, actually exactly this test is already in the rhashtable patch. > But maybe I should also change there the error print to a NL_ERR_MSG() ? Oh, really? I just sent that out, but whatever, we have enough time to fix it :-) And yes, using netlink extended ack messages here as well would be good. johannes