1 files changed, 55 insertions, 19 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 96c39e9a873c..7245f39d1e65 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1977,6 +1977,7 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
 	unsigned char *b = skb_tail_pointer(skb);
+	int ret = -EMSGSIZE;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 	if (!nlh)
@@ -2021,11 +2022,45 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 
 	return skb->len;
 
+cls_op_not_supp:
+	ret = -EOPNOTSUPP;
 out_nlmsg_trim:
 nla_put_failure:
-cls_op_not_supp:
 	nlmsg_trim(skb, b);
-	return -1;
+	return ret;
+}
+
+static struct sk_buff *tfilter_notify_prep(struct net *net,
+					   struct sk_buff *oskb,
+					   struct nlmsghdr *n,
+					   struct tcf_proto *tp,
+					   struct tcf_block *block,
+					   struct Qdisc *q, u32 parent,
+					   void *fh, int event,
+					   u32 portid, bool rtnl_held,
+					   struct netlink_ext_ack *extack)
+{
+	unsigned int size = oskb ? max(NLMSG_GOODSIZE, oskb->len) : NLMSG_GOODSIZE;
+	struct sk_buff *skb;
+	int ret;
+
+retry:
+	skb = alloc_skb(size, GFP_KERNEL);
+	if (!skb)
+		return ERR_PTR(-ENOBUFS);
+
+	ret = tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
+			    n->nlmsg_seq, n->nlmsg_flags, event, false,
+			    rtnl_held, extack);
+	if (ret <= 0) {
+		kfree_skb(skb);
+		if (ret == -EMSGSIZE) {
+			size += NLMSG_GOODSIZE;
+			goto retry;
+		}
+		return ERR_PTR(-EINVAL);
+	}
+	return skb;
 }
 
 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
@@ -2038,16 +2073,13 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 	int err = 0;
 
-	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOBUFS;
+	if (!unicast && !rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
+		return 0;
 
-	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, event,
-			  false, rtnl_held, extack) <= 0) {
-		kfree_skb(skb);
-		return -EINVAL;
-	}
+	skb = tfilter_notify_prep(net, oskb, n, tp, block, q, parent, fh, event,
+				  portid, rtnl_held, extack);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
 
 	if (unicast)
 		err = rtnl_unicast(skb, net, portid);
@@ -2067,16 +2099,14 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 	int err;
 
-	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
-	if (!skb)
-		return -ENOBUFS;
+	if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
+		return tp->ops->delete(tp, fh, last, rtnl_held, extack);
 
-	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
-			  false, rtnl_held, extack) <= 0) {
+	skb = tfilter_notify_prep(net, oskb, n, tp, block, q, parent, fh,
+				  RTM_DELTFILTER, portid, rtnl_held, extack);
+	if (IS_ERR(skb)) {
 		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
-		kfree_skb(skb);
-		return -EINVAL;
+		return PTR_ERR(skb);
 	}
 
 	err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
@@ -2891,6 +2921,9 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 	struct sk_buff *skb;
 	int err = 0;
 
+	if (!unicast && !rtnl_notify_needed(net, flags, RTNLGRP_TC))
+		return 0;
+
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!skb)
 		return -ENOBUFS;
@@ -2920,6 +2953,9 @@ static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 	struct net *net = block->net;
 	struct sk_buff *skb;
 
+	if (!rtnl_notify_needed(net, flags, RTNLGRP_TC))
+		return 0;
+
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!skb)
 		return -ENOBUFS;