1 files changed, 147 insertions, 97 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a3d7847ce69d..f0a520987085 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1036,8 +1036,8 @@ static size_t rtnl_proto_down_size(const struct net_device *dev)
 {
 	size_t size = nla_total_size(1);
 
-	if (dev->proto_down_reason)
-		size += nla_total_size(0) + nla_total_size(4);
+	/* Assume dev->proto_down_reason is not zero. */
+	size += nla_total_size(0) + nla_total_size(4);
 
 	return size;
 }
@@ -1477,13 +1477,15 @@ static int rtnl_fill_link_ifmap(struct sk_buff *skb,
 static u32 rtnl_xdp_prog_skb(struct net_device *dev)
 {
 	const struct bpf_prog *generic_xdp_prog;
+	u32 res = 0;
 
-	ASSERT_RTNL();
+	rcu_read_lock();
+	generic_xdp_prog = rcu_dereference(dev->xdp_prog);
+	if (generic_xdp_prog)
+		res = generic_xdp_prog->aux->id;
+	rcu_read_unlock();
 
-	generic_xdp_prog = rtnl_dereference(dev->xdp_prog);
-	if (!generic_xdp_prog)
-		return 0;
-	return generic_xdp_prog->aux->id;
+	return res;
 }
 
 static u32 rtnl_xdp_prog_drv(struct net_device *dev)
@@ -1603,7 +1605,8 @@ static int put_master_ifindex(struct sk_buff *skb, struct net_device *dev)
 
 	upper_dev = netdev_master_upper_dev_get_rcu(dev);
 	if (upper_dev)
-		ret = nla_put_u32(skb, IFLA_MASTER, upper_dev->ifindex);
+		ret = nla_put_u32(skb, IFLA_MASTER,
+				  READ_ONCE(upper_dev->ifindex));
 
 	rcu_read_unlock();
 	return ret;
@@ -1736,10 +1739,10 @@ static int rtnl_fill_proto_down(struct sk_buff *skb,
 	struct nlattr *pr;
 	u32 preason;
 
-	if (nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down))
+	if (nla_put_u8(skb, IFLA_PROTO_DOWN, READ_ONCE(dev->proto_down)))
 		goto nla_put_failure;
 
-	preason = dev->proto_down_reason;
+	preason = READ_ONCE(dev->proto_down_reason);
 	if (!preason)
 		return 0;
 
@@ -1812,6 +1815,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 			    u32 event, int *new_nsid, int new_ifindex,
 			    int tgt_netnsid, gfp_t gfp)
 {
+	char devname[IFNAMSIZ];
 	struct ifinfomsg *ifm;
 	struct nlmsghdr *nlh;
 	struct Qdisc *qdisc;
@@ -1824,41 +1828,51 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 	ifm = nlmsg_data(nlh);
 	ifm->ifi_family = AF_UNSPEC;
 	ifm->__ifi_pad = 0;
-	ifm->ifi_type = dev->type;
-	ifm->ifi_index = dev->ifindex;
+	ifm->ifi_type = READ_ONCE(dev->type);
+	ifm->ifi_index = READ_ONCE(dev->ifindex);
 	ifm->ifi_flags = dev_get_flags(dev);
 	ifm->ifi_change = change;
 
 	if (tgt_netnsid >= 0 && nla_put_s32(skb, IFLA_TARGET_NETNSID, tgt_netnsid))
 		goto nla_put_failure;
 
-	qdisc = rtnl_dereference(dev->qdisc);
-	if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
-	    nla_put_u32(skb, IFLA_TXQLEN, dev->tx_queue_len) ||
+	netdev_copy_name(dev, devname);
+	if (nla_put_string(skb, IFLA_IFNAME, devname))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, IFLA_TXQLEN, READ_ONCE(dev->tx_queue_len)) ||
 	    nla_put_u8(skb, IFLA_OPERSTATE,
-		       netif_running(dev) ? dev->operstate : IF_OPER_DOWN) ||
-	    nla_put_u8(skb, IFLA_LINKMODE, dev->link_mode) ||
-	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
-	    nla_put_u32(skb, IFLA_MIN_MTU, dev->min_mtu) ||
-	    nla_put_u32(skb, IFLA_MAX_MTU, dev->max_mtu) ||
-	    nla_put_u32(skb, IFLA_GROUP, dev->group) ||
-	    nla_put_u32(skb, IFLA_PROMISCUITY, dev->promiscuity) ||
-	    nla_put_u32(skb, IFLA_ALLMULTI, dev->allmulti) ||
-	    nla_put_u32(skb, IFLA_NUM_TX_QUEUES, dev->num_tx_queues) ||
-	    nla_put_u32(skb, IFLA_GSO_MAX_SEGS, dev->gso_max_segs) ||
-	    nla_put_u32(skb, IFLA_GSO_MAX_SIZE, dev->gso_max_size) ||
-	    nla_put_u32(skb, IFLA_GRO_MAX_SIZE, dev->gro_max_size) ||
-	    nla_put_u32(skb, IFLA_GSO_IPV4_MAX_SIZE, dev->gso_ipv4_max_size) ||
-	    nla_put_u32(skb, IFLA_GRO_IPV4_MAX_SIZE, dev->gro_ipv4_max_size) ||
-	    nla_put_u32(skb, IFLA_TSO_MAX_SIZE, dev->tso_max_size) ||
-	    nla_put_u32(skb, IFLA_TSO_MAX_SEGS, dev->tso_max_segs) ||
+		       netif_running(dev) ? READ_ONCE(dev->operstate) :
+					    IF_OPER_DOWN) ||
+	    nla_put_u8(skb, IFLA_LINKMODE, READ_ONCE(dev->link_mode)) ||
+	    nla_put_u32(skb, IFLA_MTU, READ_ONCE(dev->mtu)) ||
+	    nla_put_u32(skb, IFLA_MIN_MTU, READ_ONCE(dev->min_mtu)) ||
+	    nla_put_u32(skb, IFLA_MAX_MTU, READ_ONCE(dev->max_mtu)) ||
+	    nla_put_u32(skb, IFLA_GROUP, READ_ONCE(dev->group)) ||
+	    nla_put_u32(skb, IFLA_PROMISCUITY, READ_ONCE(dev->promiscuity)) ||
+	    nla_put_u32(skb, IFLA_ALLMULTI, READ_ONCE(dev->allmulti)) ||
+	    nla_put_u32(skb, IFLA_NUM_TX_QUEUES,
+			READ_ONCE(dev->num_tx_queues)) ||
+	    nla_put_u32(skb, IFLA_GSO_MAX_SEGS,
+			READ_ONCE(dev->gso_max_segs)) ||
+	    nla_put_u32(skb, IFLA_GSO_MAX_SIZE,
+			READ_ONCE(dev->gso_max_size)) ||
+	    nla_put_u32(skb, IFLA_GRO_MAX_SIZE,
+			READ_ONCE(dev->gro_max_size)) ||
+	    nla_put_u32(skb, IFLA_GSO_IPV4_MAX_SIZE,
+			READ_ONCE(dev->gso_ipv4_max_size)) ||
+	    nla_put_u32(skb, IFLA_GRO_IPV4_MAX_SIZE,
+			READ_ONCE(dev->gro_ipv4_max_size)) ||
+	    nla_put_u32(skb, IFLA_TSO_MAX_SIZE,
+			READ_ONCE(dev->tso_max_size)) ||
+	    nla_put_u32(skb, IFLA_TSO_MAX_SEGS,
+			READ_ONCE(dev->tso_max_segs)) ||
 #ifdef CONFIG_RPS
-	    nla_put_u32(skb, IFLA_NUM_RX_QUEUES, dev->num_rx_queues) ||
+	    nla_put_u32(skb, IFLA_NUM_RX_QUEUES,
+			READ_ONCE(dev->num_rx_queues)) ||
 #endif
 	    put_master_ifindex(skb, dev) ||
 	    nla_put_u8(skb, IFLA_CARRIER, netif_carrier_ok(dev)) ||
-	    (qdisc &&
-	     nla_put_string(skb, IFLA_QDISC, qdisc->ops->id)) ||
 	    nla_put_ifalias(skb, dev) ||
 	    nla_put_u32(skb, IFLA_CARRIER_CHANGES,
 			atomic_read(&dev->carrier_up_count) +
@@ -1909,9 +1923,6 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 			goto nla_put_failure;
 	}
 
-	if (rtnl_fill_link_netnsid(skb, dev, src_net, gfp))
-		goto nla_put_failure;
-
 	if (new_nsid &&
 	    nla_put_s32(skb, IFLA_NEW_NETNSID, *new_nsid) < 0)
 		goto nla_put_failure;
@@ -1924,6 +1935,11 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 		goto nla_put_failure;
 
 	rcu_read_lock();
+	if (rtnl_fill_link_netnsid(skb, dev, src_net, GFP_ATOMIC))
+		goto nla_put_failure_rcu;
+	qdisc = rcu_dereference(dev->qdisc);
+	if (qdisc && nla_put_string(skb, IFLA_QDISC, qdisc->ops->id))
+		goto nla_put_failure_rcu;
 	if (rtnl_fill_link_af(skb, dev, ext_filter_mask))
 		goto nla_put_failure_rcu;
 	if (rtnl_fill_link_ifmap(skb, dev))
@@ -2530,7 +2546,7 @@ static int do_setvfinfo(struct net_device *dev, struct nlattr **tb)
 
 		nla_for_each_nested(attr, tb[IFLA_VF_VLAN_LIST], rem) {
 			if (nla_type(attr) != IFLA_VF_VLAN_INFO ||
-			    nla_len(attr) < NLA_HDRLEN) {
+			    nla_len(attr) < sizeof(struct ifla_vf_vlan_info)) {
 				return -EINVAL;
 			}
 			if (len >= MAX_VLAN_LIST_LEN)
@@ -2708,7 +2724,7 @@ static int do_set_proto_down(struct net_device *dev,
 	bool proto_down;
 	int err;
 
-	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN)) {
+	if (!dev->change_proto_down) {
 		NL_SET_ERR_MSG(extack,  "Protodown not supported by device");
 		return -EOPNOTSUPP;
 	}
@@ -3272,7 +3288,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (ifm->ifi_index > 0)
 		dev = __dev_get_by_index(tgt_net, ifm->ifi_index);
 	else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME])
-		dev = rtnl_dev_get(net, tb);
+		dev = rtnl_dev_get(tgt_net, tb);
 	else if (tb[IFLA_GROUP])
 		err = rtnl_group_dellink(tgt_net, nla_get_u32(tb[IFLA_GROUP]));
 	else
@@ -3953,22 +3969,28 @@ static int rtnl_dellinkprop(struct sk_buff *skb, struct nlmsghdr *nlh,
 	return rtnl_linkprop(RTM_DELLINKPROP, skb, nlh, extack);
 }
 
-static u32 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
+static noinline_for_stack u32 rtnl_calcit(struct sk_buff *skb,
+					  struct nlmsghdr *nlh)
 {
 	struct net *net = sock_net(skb->sk);
 	size_t min_ifinfo_dump_size = 0;
-	struct nlattr *tb[IFLA_MAX+1];
 	u32 ext_filter_mask = 0;
 	struct net_device *dev;
-	int hdrlen;
+	struct nlattr *nla;
+	int hdrlen, rem;
 
 	/* Same kernel<->userspace interface hack as in rtnl_dump_ifinfo. */
 	hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ?
 		 sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
 
-	if (nlmsg_parse_deprecated(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) {
-		if (tb[IFLA_EXT_MASK])
-			ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
+	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+		return NLMSG_GOODSIZE;
+
+	nla_for_each_attr_type(nla, IFLA_EXT_MASK,
+			       nlmsg_attrdata(nlh, hdrlen),
+			       nlmsg_attrlen(nlh, hdrlen), rem) {
+		if (nla_len(nla) == sizeof(u32))
+			ext_filter_mask = nla_get_u32(nla);
 	}
 
 	if (!ext_filter_mask)
@@ -4065,8 +4087,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 	}
 	return skb;
 errout:
-	if (err < 0)
-		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
+	rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 	return NULL;
 }
 
@@ -5245,15 +5266,14 @@ static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
 	if (br_spec) {
-		nla_for_each_nested(attr, br_spec, rem) {
-			if (nla_type(attr) == IFLA_BRIDGE_FLAGS) {
-				if (nla_len(attr) < sizeof(flags))
-					return -EINVAL;
+		nla_for_each_nested_type(attr, IFLA_BRIDGE_FLAGS, br_spec,
+					 rem) {
+			if (nla_len(attr) < sizeof(flags))
+				return -EINVAL;
 
-				have_flags = true;
-				flags = nla_get_u16(attr);
-				break;
-			}
+			have_flags = true;
+			flags = nla_get_u16(attr);
+			break;
 		}
 	}
 
@@ -5962,19 +5982,17 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh,
 static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct netlink_ext_ack *extack = cb->extack;
-	int h, s_h, err, s_idx, s_idxattr, s_prividx;
 	struct rtnl_stats_dump_filters filters;
 	struct net *net = sock_net(skb->sk);
 	unsigned int flags = NLM_F_MULTI;
 	struct if_stats_msg *ifsm;
-	struct hlist_head *head;
+	struct {
+		unsigned long ifindex;
+		int idxattr;
+		int prividx;
+	} *ctx = (void *)cb->ctx;
 	struct net_device *dev;
-	int idx = 0;
-
-	s_h = cb->args[0];
-	s_idx = cb->args[1];
-	s_idxattr = cb->args[2];
-	s_prividx = cb->args[3];
+	int err;
 
 	cb->seq = net->dev_base_seq;
 
@@ -5993,39 +6011,26 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	if (err)
 		return err;
 
-	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
-		idx = 0;
-		head = &net->dev_index_head[h];
-		hlist_for_each_entry(dev, head, index_hlist) {
-			if (idx < s_idx)
-				goto cont;
-			err = rtnl_fill_statsinfo(skb, dev, RTM_NEWSTATS,
-						  NETLINK_CB(cb->skb).portid,
-						  cb->nlh->nlmsg_seq, 0,
-						  flags, &filters,
-						  &s_idxattr, &s_prividx,
-						  extack);
-			/* If we ran out of room on the first message,
-			 * we're in trouble
-			 */
-			WARN_ON((err == -EMSGSIZE) && (skb->len == 0));
+	for_each_netdev_dump(net, dev, ctx->ifindex) {
+		err = rtnl_fill_statsinfo(skb, dev, RTM_NEWSTATS,
+					  NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, 0,
+					  flags, &filters,
+					  &ctx->idxattr, &ctx->prividx,
+					  extack);
+		/* If we ran out of room on the first message,
+		 * we're in trouble.
+		 */
+		WARN_ON((err == -EMSGSIZE) && (skb->len == 0));
 
-			if (err < 0)
-				goto out;
-			s_prividx = 0;
-			s_idxattr = 0;
-			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-cont:
-			idx++;
-		}
+		if (err < 0)
+			break;
+		ctx->prividx = 0;
+		ctx->idxattr = 0;
+		nl_dump_check_consistent(cb, nlmsg_hdr(skb));
 	}
-out:
-	cb->args[3] = s_prividx;
-	cb->args[2] = s_idxattr;
-	cb->args[1] = idx;
-	cb->args[0] = h;
 
-	return skb->len;
+	return err;
 }
 
 void rtnl_offload_xstats_notify(struct net_device *dev)
@@ -6484,6 +6489,52 @@ static int rtnl_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 /* Process one rtnetlink message. */
 
+static int rtnl_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	const bool needs_lock = !(cb->flags & RTNL_FLAG_DUMP_UNLOCKED);
+	rtnl_dumpit_func dumpit = cb->data;
+	int err;
+
+	/* Previous iteration have already finished, avoid calling->dumpit()
+	 * again, it may not expect to be called after it reached the end.
+	 */
+	if (!dumpit)
+		return 0;
+
+	if (needs_lock)
+		rtnl_lock();
+	err = dumpit(skb, cb);
+	if (needs_lock)
+		rtnl_unlock();
+
+	/* Old dump handlers used to send NLM_DONE as in a separate recvmsg().
+	 * Some applications which parse netlink manually depend on this.
+	 */
+	if (cb->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE) {
+		if (err < 0 && err != -EMSGSIZE)
+			return err;
+		if (!err)
+			cb->data = NULL;
+
+		return skb->len;
+	}
+	return err;
+}
+
+static int rtnetlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+				const struct nlmsghdr *nlh,
+				struct netlink_dump_control *control)
+{
+	if (control->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE ||
+	    !(control->flags & RTNL_FLAG_DUMP_UNLOCKED)) {
+		WARN_ON(control->data);
+		control->data = control->dump;
+		control->dump = rtnl_dumpit;
+	}
+
+	return netlink_dump_start(ssk, skb, nlh, control);
+}
+
 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
@@ -6548,7 +6599,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 				.module		= owner,
 				.flags		= flags,
 			};
-			err = netlink_dump_start(rtnl, skb, nlh, &c);
+			err = rtnetlink_dump_start(rtnl, skb, nlh, &c);
 			/* netlink_dump_start() will keep a reference on
 			 * module if dump is still in progress.
 			 */
@@ -6663,7 +6714,6 @@ static int __net_init rtnetlink_net_init(struct net *net)
 	struct netlink_kernel_cfg cfg = {
 		.groups		= RTNLGRP_MAX,
 		.input		= rtnetlink_rcv,
-		.cb_mutex	= &rtnl_mutex,
 		.flags		= NL_CFG_F_NONROOT_RECV,
 		.bind		= rtnetlink_bind,
 	};
@@ -6694,7 +6744,7 @@ void __init rtnetlink_init(void)
 	register_netdevice_notifier(&rtnetlink_dev_notifier);
 
 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
-		      rtnl_dump_ifinfo, 0);
+		      rtnl_dump_ifinfo, RTNL_FLAG_DUMP_SPLIT_NLM_DONE);
 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, 0);