Re: [net-next][PATCH] net/ipv4: fix a net leak

On 10/25/18 12:43 PM, Bjørn Mork wrote:

inet_valid_dump_ifaddr_req() will bail out with an error, but only
*after* setting fillargs->netnsid:

                if (i == IFA_TARGET_NETNSID) {
                        struct net *net;

                        fillargs->netnsid = nla_get_s32(tb[i]);

                        net = rtnl_get_net_ns_capable(sk, fillargs->netnsid);
                        if (IS_ERR(net)) {
                                NL_SET_ERR_MSG(extack, "ipv4: Invalid target network namespace id");
                                return PTR_ERR(net);
                        }
                        *tgt_net = net;
                } else {



So inet_dump_ifaddr() ends up doing put_net(tgt_net):


                err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
                                                 skb->sk, cb);
                if (err < 0)
                        goto put_tgt_net;
..
put_tgt_net:
        if (fillargs.netnsid >= 0)
                put_net(tgt_net);



I believe you should set fillargs->netnsid back to -1 in the
inet_valid_dump_ifaddr_req() error path, or use a temp variable to avoid
changing it unless get_net is successful.

good point. either use of an intermediate or resetting nsid on failure.
Will you send a patch to fix ipv4 and v6?

Thanks,