Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 640 insertions, 0 deletions

diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
new file mode 100644
index 000000000..f4b261844
--- /dev/null
+++ b/net/ipv6/addrlabel.c
@@ -0,0 +1,640 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPv6 Address Label subsystem
+ * for the IPv6 "Default" Source Address Selection
+ *
+ * Copyright (C)2007 USAGI/WIDE Project
+ */
+/*
+ * Author:
+ *	YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <net/addrconf.h>
+#include <linux/if_addrlabel.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+/*
+ * Policy Table
+ */
+struct ip6addrlbl_entry {
+	struct in6_addr prefix;
+	int prefixlen;
+	int ifindex;
+	int addrtype;
+	u32 label;
+	struct hlist_node list;
+	struct rcu_head rcu;
+};
+
+/*
+ * Default policy table (RFC6724 + extensions)
+ *
+ * prefix		addr_type	label
+ * -------------------------------------------------------------------------
+ * ::1/128		LOOPBACK	0
+ * ::/0			N/A		1
+ * 2002::/16		N/A		2
+ * ::/96		COMPATv4	3
+ * ::ffff:0:0/96	V4MAPPED	4
+ * fc00::/7		N/A		5		ULA (RFC 4193)
+ * 2001::/32		N/A		6		Teredo (RFC 4380)
+ * 2001:10::/28		N/A		7		ORCHID (RFC 4843)
+ * fec0::/10		N/A		11		Site-local
+ *							(deprecated by RFC3879)
+ * 3ffe::/16		N/A		12		6bone
+ *
+ * Note: 0xffffffff is used if we do not have any policies.
+ * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
+ */
+
+#define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL
+
+static const __net_initconst struct ip6addrlbl_init_table
+{
+	const struct in6_addr *prefix;
+	int prefixlen;
+	u32 label;
+} ip6addrlbl_init_table[] = {
+	{	/* ::/0 */
+		.prefix = &in6addr_any,
+		.label = 1,
+	}, {	/* fc00::/7 */
+		.prefix = &(struct in6_addr){ { { 0xfc } } } ,
+		.prefixlen = 7,
+		.label = 5,
+	}, {	/* fec0::/10 */
+		.prefix = &(struct in6_addr){ { { 0xfe, 0xc0 } } },
+		.prefixlen = 10,
+		.label = 11,
+	}, {	/* 2002::/16 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x02 } } },
+		.prefixlen = 16,
+		.label = 2,
+	}, {	/* 3ffe::/16 */
+		.prefix = &(struct in6_addr){ { { 0x3f, 0xfe } } },
+		.prefixlen = 16,
+		.label = 12,
+	}, {	/* 2001::/32 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01 } } },
+		.prefixlen = 32,
+		.label = 6,
+	}, {	/* 2001:10::/28 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01, 0x00, 0x10 } } },
+		.prefixlen = 28,
+		.label = 7,
+	}, {	/* ::ffff:0:0 */
+		.prefix = &(struct in6_addr){ { { [10] = 0xff, [11] = 0xff } } },
+		.prefixlen = 96,
+		.label = 4,
+	}, {	/* ::/96 */
+		.prefix = &in6addr_any,
+		.prefixlen = 96,
+		.label = 3,
+	}, {	/* ::1/128 */
+		.prefix = &in6addr_loopback,
+		.prefixlen = 128,
+		.label = 0,
+	}
+};
+
+/* Find label */
+static bool __ip6addrlbl_match(const struct ip6addrlbl_entry *p,
+			       const struct in6_addr *addr,
+			       int addrtype, int ifindex)
+{
+	if (p->ifindex && p->ifindex != ifindex)
+		return false;
+	if (p->addrtype && p->addrtype != addrtype)
+		return false;
+	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
+		return false;
+	return true;
+}
+
+static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
+						  const struct in6_addr *addr,
+						  int type, int ifindex)
+{
+	struct ip6addrlbl_entry *p;
+
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (__ip6addrlbl_match(p, addr, type, ifindex))
+			return p;
+	}
+	return NULL;
+}
+
+u32 ipv6_addr_label(struct net *net,
+		    const struct in6_addr *addr, int type, int ifindex)
+{
+	u32 label;
+	struct ip6addrlbl_entry *p;
+
+	type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, type, ifindex);
+	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
+	rcu_read_unlock();
+
+	net_dbg_ratelimited("%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n", __func__, addr, type,
+			    ifindex, label);
+
+	return label;
+}
+
+/* allocate one entry */
+static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
+						 int prefixlen, int ifindex,
+						 u32 label)
+{
+	struct ip6addrlbl_entry *newp;
+	int addrtype;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n", __func__,
+			    prefix, prefixlen, ifindex, (unsigned int)label);
+
+	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
+
+	switch (addrtype) {
+	case IPV6_ADDR_MAPPED:
+		if (prefixlen > 96)
+			return ERR_PTR(-EINVAL);
+		if (prefixlen < 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_COMPATv4:
+		if (prefixlen != 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_LOOPBACK:
+		if (prefixlen != 128)
+			addrtype = 0;
+		break;
+	}
+
+	newp = kmalloc_obj(*newp);
+	if (!newp)
+		return ERR_PTR(-ENOMEM);
+
+	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
+	newp->prefixlen = prefixlen;
+	newp->ifindex = ifindex;
+	newp->addrtype = addrtype;
+	newp->label = label;
+	INIT_HLIST_NODE(&newp->list);
+	return newp;
+}
+
+/* add a label */
+static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp,
+			    int replace)
+{
+	struct ip6addrlbl_entry *last = NULL, *p = NULL;
+	struct hlist_node *n;
+	int ret = 0;
+
+	net_dbg_ratelimited("%s(newp=%p, replace=%d)\n", __func__, newp, replace);
+
+	hlist_for_each_entry_safe(p, n,	&net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == newp->prefixlen &&
+		    p->ifindex == newp->ifindex &&
+		    ipv6_addr_equal(&p->prefix, &newp->prefix)) {
+			if (!replace) {
+				ret = -EEXIST;
+				goto out;
+			}
+			hlist_replace_rcu(&p->list, &newp->list);
+			kfree_rcu(p, rcu);
+			goto out;
+		} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
+			   (p->prefixlen < newp->prefixlen)) {
+			hlist_add_before_rcu(&newp->list, &p->list);
+			goto out;
+		}
+		last = p;
+	}
+	if (last)
+		hlist_add_behind_rcu(&newp->list, &last->list);
+	else
+		hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head);
+out:
+	if (!ret)
+		WRITE_ONCE(net->ipv6.ip6addrlbl_table.seq,
+			   net->ipv6.ip6addrlbl_table.seq + 1);
+	return ret;
+}
+
+/* add a label */
+static int ip6addrlbl_add(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex, u32 label, int replace)
+{
+	struct ip6addrlbl_entry *newp;
+	int ret = 0;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
+			    __func__, prefix, prefixlen, ifindex, (unsigned int)label, replace);
+
+	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
+	if (IS_ERR(newp))
+		return PTR_ERR(newp);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_add(net, newp, replace);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	if (ret)
+		kfree(newp);
+	return ret;
+}
+
+/* remove a label */
+static int __ip6addrlbl_del(struct net *net,
+			    const struct in6_addr *prefix, int prefixlen,
+			    int ifindex)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int ret = -ESRCH;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
+			    prefixlen, ifindex);
+
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == prefixlen &&
+		    p->ifindex == ifindex &&
+		    ipv6_addr_equal(&p->prefix, prefix)) {
+			hlist_del_rcu(&p->list);
+			kfree_rcu(p, rcu);
+			ret = 0;
+			break;
+		}
+	}
+	return ret;
+}
+
+static int ip6addrlbl_del(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex)
+{
+	struct in6_addr prefix_buf;
+	int ret;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
+			    prefixlen, ifindex);
+
+	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	return ret;
+}
+
+/* add default label */
+static int __net_init ip6addrlbl_net_init(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int err;
+	int i;
+
+	spin_lock_init(&net->ipv6.ip6addrlbl_table.lock);
+	INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);
+
+	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
+		err = ip6addrlbl_add(net,
+				     ip6addrlbl_init_table[i].prefix,
+				     ip6addrlbl_init_table[i].prefixlen,
+				     0,
+				     ip6addrlbl_init_table[i].label, 0);
+		if (err)
+			goto err_ip6addrlbl_add;
+	}
+	return 0;
+
+err_ip6addrlbl_add:
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	return err;
+}
+
+static void __net_exit ip6addrlbl_net_exit(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+
+	/* Remove all labels belonging to the exiting net */
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+}
+
+static struct pernet_operations ipv6_addr_label_ops = {
+	.init = ip6addrlbl_net_init,
+	.exit = ip6addrlbl_net_exit,
+};
+
+int __init ipv6_addr_label_init(void)
+{
+	return register_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+void ipv6_addr_label_cleanup(void)
+{
+	unregister_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
+	[IFAL_ADDRESS]		= { .len = sizeof(struct in6_addr), },
+	[IFAL_LABEL]		= { .len = sizeof(u32), },
+};
+
+static bool addrlbl_ifindex_exists(struct net *net, int ifindex)
+{
+
+	struct net_device *dev;
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, ifindex);
+	rcu_read_unlock();
+
+	return dev != NULL;
+}
+
+static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *pfx;
+	u32 label;
+	int err = 0;
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb, IFAL_MAX,
+				     ifal_policy, extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen > 128)
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	pfx = nla_data(tb[IFAL_ADDRESS]);
+
+	if (!tb[IFAL_LABEL])
+		return -EINVAL;
+	label = nla_get_u32(tb[IFAL_LABEL]);
+	if (label == IPV6_ADDR_LABEL_DEFAULT)
+		return -EINVAL;
+
+	switch (nlh->nlmsg_type) {
+	case RTM_NEWADDRLABEL:
+		if (ifal->ifal_index &&
+		    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+			return -EINVAL;
+
+		err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index, label,
+				     nlh->nlmsg_flags & NLM_F_REPLACE);
+		break;
+	case RTM_DELADDRLABEL:
+		err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+	}
+	return err;
+}
+
+static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
+			      int prefixlen, int ifindex, u32 lseq)
+{
+	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
+	ifal->ifal_family = AF_INET6;
+	ifal->__ifal_reserved = 0;
+	ifal->ifal_prefixlen = prefixlen;
+	ifal->ifal_flags = 0;
+	ifal->ifal_index = ifindex;
+	ifal->ifal_seq = lseq;
+};
+
+static int ip6addrlbl_fill(struct sk_buff *skb,
+			   const struct ip6addrlbl_entry *p,
+			   u32 lseq,
+			   u32 portid, u32 seq, int event,
+			   unsigned int flags)
+{
+	struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
+					 sizeof(struct ifaddrlblmsg), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
+
+	if (nla_put_in6_addr(skb, IFAL_ADDRESS, &p->prefix) < 0 ||
+	    nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
+		nlmsg_cancel(skb, nlh);
+		return -EMSGSIZE;
+	}
+
+	nlmsg_end(skb, nlh);
+	return 0;
+}
+
+static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh,
+				     struct netlink_ext_ack *extack)
+{
+	struct ifaddrlblmsg *ifal;
+
+	ifal = nlmsg_payload(nlh, sizeof(*ifal));
+	if (!ifal) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request");
+		return -EINVAL;
+	}
+
+	if (ifal->__ifal_reserved || ifal->ifal_prefixlen ||
+	    ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request");
+		return -EINVAL;
+	}
+
+	if (nlmsg_attrlen(nlh, sizeof(*ifal))) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump request");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	const struct nlmsghdr *nlh = cb->nlh;
+	struct net *net = sock_net(skb->sk);
+	struct ip6addrlbl_entry *p;
+	int idx = 0, s_idx = cb->args[0];
+	int err = 0;
+	u32 lseq;
+
+	if (cb->strict_check) {
+		err = ip6addrlbl_valid_dump_req(nlh, cb->extack);
+		if (err < 0)
+			return err;
+	}
+
+	rcu_read_lock();
+	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (idx >= s_idx) {
+			err = ip6addrlbl_fill(skb, p,
+					      lseq,
+					      NETLINK_CB(cb->skb).portid,
+					      nlh->nlmsg_seq,
+					      RTM_NEWADDRLABEL,
+					      NLM_F_MULTI);
+			if (err < 0)
+				break;
+		}
+		idx++;
+	}
+	rcu_read_unlock();
+	cb->args[0] = idx;
+	return err;
+}
+
+static inline int ip6addrlbl_msgsize(void)
+{
+	return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
+		+ nla_total_size(16)	/* IFAL_ADDRESS */
+		+ nla_total_size(4);	/* IFAL_LABEL */
+}
+
+static int ip6addrlbl_valid_get_req(struct sk_buff *skb,
+				    const struct nlmsghdr *nlh,
+				    struct nlattr **tb,
+				    struct netlink_ext_ack *extack)
+{
+	struct ifaddrlblmsg *ifal;
+	int i, err;
+
+	ifal = nlmsg_payload(nlh, sizeof(*ifal));
+	if (!ifal) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid header for addrlabel get request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb,
+					      IFAL_MAX, ifal_policy, extack);
+
+	if (ifal->__ifal_reserved || ifal->ifal_flags || ifal->ifal_seq) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for addrlabel get request");
+		return -EINVAL;
+	}
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifal), tb, IFAL_MAX,
+					    ifal_policy, extack);
+	if (err)
+		return err;
+
+	for (i = 0; i <= IFAL_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case IFAL_ADDRESS:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in addrlabel get request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *addr;
+	u32 lseq;
+	int err = 0;
+	struct ip6addrlbl_entry *p;
+	struct sk_buff *skb;
+
+	err = ip6addrlbl_valid_get_req(in_skb, nlh, tb, extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen != 128)
+		return -EINVAL;
+
+	if (ifal->ifal_index &&
+	    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	addr = nla_data(tb[IFAL_ADDRESS]);
+
+	skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	err = -ESRCH;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
+	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
+	if (p)
+		err = ip6addrlbl_fill(skb, p, lseq,
+				      NETLINK_CB(in_skb).portid,
+				      nlh->nlmsg_seq,
+				      RTM_NEWADDRLABEL, 0);
+	rcu_read_unlock();
+
+	if (err < 0) {
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+	} else {
+		err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+	}
+	return err;
+}
+
+static const struct rtnl_msg_handler ipv6_adddr_label_rtnl_msg_handlers[] __initconst_or_module = {
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_NEWADDRLABEL,
+	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_DELADDRLABEL,
+	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_GETADDRLABEL,
+	 .doit = ip6addrlbl_get, .dumpit = ip6addrlbl_dump,
+	 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
+};
+
+int __init ipv6_addr_label_rtnl_register(void)
+{
+	return rtnl_register_many(ipv6_adddr_label_rtnl_msg_handlers);
+}