Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

Steffen Klassert says:

====================
1) Refactor selftests to use an array of structs in xfrm_fill_key().
   From Gautam Menghani.

2) Drop an unused argument from xfrm_policy_match.
   From Hongbin Wang.

3) Support collect metadata mode for xfrm interfaces.
   From Eyal Birger.

4) Add netlink extack support to xfrm.
   From Sabrina Dubroca.

Please note, there is a merge conflict in:

include/net/dst_metadata.h

between commit:

0a28bfd4971f ("net/macsec: Add MACsec skb_metadata_dst Tx Data path support")

from the net-next tree and commit:

5182a5d48c3d ("net: allow storing xfrm interface metadata in metadata_dst")

from the ipsec-next tree.

Can be solved as done in linux-next.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 503 insertions, 175 deletions

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 637ca8838436..5f5aafd418af 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -207,7 +207,8 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
 
 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
-		       struct xfrm_user_offload *xuo)
+		       struct xfrm_user_offload *xuo,
+		       struct netlink_ext_ack *extack)
 {
 	int err;
 	struct dst_entry *dst;
@@ -216,15 +217,21 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	xfrm_address_t *saddr;
 	xfrm_address_t *daddr;
 
-	if (!x->type_offload)
+	if (!x->type_offload) {
+		NL_SET_ERR_MSG(extack, "Type doesn't support offload");
 		return -EINVAL;
+	}
 
 	/* We don't yet support UDP encapsulation and TFC padding. */
-	if (x->encap || x->tfcpad)
+	if (x->encap || x->tfcpad) {
+		NL_SET_ERR_MSG(extack, "Encapsulation and TFC padding can't be offloaded");
 		return -EINVAL;
+	}
 
-	if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND))
+	if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND)) {
+		NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
 		return -EINVAL;
+	}
 
 	dev = dev_get_by_index(net, xuo->ifindex);
 	if (!dev) {
@@ -256,6 +263,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 
 	if (x->props.flags & XFRM_STATE_ESN &&
 	    !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
+		NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN");
 		xso->dev = NULL;
 		dev_put(dev);
 		return -EINVAL;
@@ -277,8 +285,10 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		xso->real_dev = NULL;
 		netdev_put(dev, &xso->dev_tracker);
 
-		if (err != -EOPNOTSUPP)
+		if (err != -EOPNOTSUPP) {
+			NL_SET_ERR_MSG(extack, "Device failed to offload this state");
 			return err;
+		}
 	}
 
 	return 0;
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index b2f4ec9c537f..a3cf85d3f296 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -20,6 +20,7 @@
 #include <net/xfrm.h>
 #include <net/ip_tunnels.h>
 #include <net/ip6_tunnel.h>
+#include <net/dst_metadata.h>
 
 #include "xfrm_inout.h"
 
@@ -719,7 +720,8 @@ resume:
 		sp = skb_sec_path(skb);
 		if (sp)
 			sp->olen = 0;
-		skb_dst_drop(skb);
+		if (skb_valid_dst(skb))
+			skb_dst_drop(skb);
 		gro_cells_receive(&gro_cells, skb);
 		return 0;
 	} else {
@@ -737,7 +739,8 @@ resume:
 			sp = skb_sec_path(skb);
 			if (sp)
 				sp->olen = 0;
-			skb_dst_drop(skb);
+			if (skb_valid_dst(skb))
+				skb_dst_drop(skb);
 			gro_cells_receive(&gro_cells, skb);
 			return err;
 		}
diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index 5113fa0fbcee..5a67b120c4db 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -41,6 +41,7 @@
 #include <net/addrconf.h>
 #include <net/xfrm.h>
 #include <net/net_namespace.h>
+#include <net/dst_metadata.h>
 #include <net/netns/generic.h>
 #include <linux/etherdevice.h>
 
@@ -56,6 +57,89 @@ static const struct net_device_ops xfrmi_netdev_ops;
 struct xfrmi_net {
 	/* lists for storing interfaces in use */
 	struct xfrm_if __rcu *xfrmi[XFRMI_HASH_SIZE];
+	struct xfrm_if __rcu *collect_md_xfrmi;
+};
+
+static const struct nla_policy xfrm_lwt_policy[LWT_XFRM_MAX + 1] = {
+	[LWT_XFRM_IF_ID]	= NLA_POLICY_MIN(NLA_U32, 1),
+	[LWT_XFRM_LINK]		= NLA_POLICY_MIN(NLA_U32, 1),
+};
+
+static void xfrmi_destroy_state(struct lwtunnel_state *lwt)
+{
+}
+
+static int xfrmi_build_state(struct net *net, struct nlattr *nla,
+			     unsigned int family, const void *cfg,
+			     struct lwtunnel_state **ts,
+			     struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[LWT_XFRM_MAX + 1];
+	struct lwtunnel_state *new_state;
+	struct xfrm_md_info *info;
+	int ret;
+
+	ret = nla_parse_nested(tb, LWT_XFRM_MAX, nla, xfrm_lwt_policy, extack);
+	if (ret < 0)
+		return ret;
+
+	if (!tb[LWT_XFRM_IF_ID]) {
+		NL_SET_ERR_MSG(extack, "if_id must be set");
+		return -EINVAL;
+	}
+
+	new_state = lwtunnel_state_alloc(sizeof(*info));
+	if (!new_state) {
+		NL_SET_ERR_MSG(extack, "failed to create encap info");
+		return -ENOMEM;
+	}
+
+	new_state->type = LWTUNNEL_ENCAP_XFRM;
+
+	info = lwt_xfrm_info(new_state);
+
+	info->if_id = nla_get_u32(tb[LWT_XFRM_IF_ID]);
+
+	if (tb[LWT_XFRM_LINK])
+		info->link = nla_get_u32(tb[LWT_XFRM_LINK]);
+
+	*ts = new_state;
+	return 0;
+}
+
+static int xfrmi_fill_encap_info(struct sk_buff *skb,
+				 struct lwtunnel_state *lwt)
+{
+	struct xfrm_md_info *info = lwt_xfrm_info(lwt);
+
+	if (nla_put_u32(skb, LWT_XFRM_IF_ID, info->if_id) ||
+	    (info->link && nla_put_u32(skb, LWT_XFRM_LINK, info->link)))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int xfrmi_encap_nlsize(struct lwtunnel_state *lwtstate)
+{
+	return nla_total_size(sizeof(u32)) + /* LWT_XFRM_IF_ID */
+		nla_total_size(sizeof(u32)); /* LWT_XFRM_LINK */
+}
+
+static int xfrmi_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
+{
+	struct xfrm_md_info *a_info = lwt_xfrm_info(a);
+	struct xfrm_md_info *b_info = lwt_xfrm_info(b);
+
+	return memcmp(a_info, b_info, sizeof(*a_info));
+}
+
+static const struct lwtunnel_encap_ops xfrmi_encap_ops = {
+	.build_state	= xfrmi_build_state,
+	.destroy_state	= xfrmi_destroy_state,
+	.fill_encap	= xfrmi_fill_encap_info,
+	.get_encap_size = xfrmi_encap_nlsize,
+	.cmp_encap	= xfrmi_encap_cmp,
+	.owner		= THIS_MODULE,
 };
 
 #define for_each_xfrmi_rcu(start, xi) \
@@ -77,17 +161,23 @@ static struct xfrm_if *xfrmi_lookup(struct net *net, struct xfrm_state *x)
 			return xi;
 	}
 
+	xi = rcu_dereference(xfrmn->collect_md_xfrmi);
+	if (xi && (xi->dev->flags & IFF_UP))
+		return xi;
+
 	return NULL;
 }
 
-static struct xfrm_if *xfrmi_decode_session(struct sk_buff *skb,
-					    unsigned short family)
+static bool xfrmi_decode_session(struct sk_buff *skb,
+				 unsigned short family,
+				 struct xfrm_if_decode_session_result *res)
 {
 	struct net_device *dev;
+	struct xfrm_if *xi;
 	int ifindex = 0;
 
 	if (!secpath_exists(skb) || !skb->dev)
-		return NULL;
+		return false;
 
 	switch (family) {
 	case AF_INET6:
@@ -107,11 +197,18 @@ static struct xfrm_if *xfrmi_decode_session(struct sk_buff *skb,
 	}
 
 	if (!dev || !(dev->flags & IFF_UP))
-		return NULL;
+		return false;
 	if (dev->netdev_ops != &xfrmi_netdev_ops)
-		return NULL;
+		return false;
 
-	return netdev_priv(dev);
+	xi = netdev_priv(dev);
+	res->net = xi->net;
+
+	if (xi->p.collect_md)
+		res->if_id = xfrm_input_state(skb)->if_id;
+	else
+		res->if_id = xi->p.if_id;
+	return true;
 }
 
 static void xfrmi_link(struct xfrmi_net *xfrmn, struct xfrm_if *xi)
@@ -157,7 +254,10 @@ static int xfrmi_create(struct net_device *dev)
 	if (err < 0)
 		goto out;
 
-	xfrmi_link(xfrmn, xi);
+	if (xi->p.collect_md)
+		rcu_assign_pointer(xfrmn->collect_md_xfrmi, xi);
+	else
+		xfrmi_link(xfrmn, xi);
 
 	return 0;
 
@@ -185,7 +285,10 @@ static void xfrmi_dev_uninit(struct net_device *dev)
 	struct xfrm_if *xi = netdev_priv(dev);
 	struct xfrmi_net *xfrmn = net_generic(xi->net, xfrmi_net_id);
 
-	xfrmi_unlink(xfrmn, xi);
+	if (xi->p.collect_md)
+		RCU_INIT_POINTER(xfrmn->collect_md_xfrmi, NULL);
+	else
+		xfrmi_unlink(xfrmn, xi);
 }
 
 static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
@@ -214,6 +317,7 @@ static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 	struct xfrm_state *x;
 	struct xfrm_if *xi;
 	bool xnet;
+	int link;
 
 	if (err && !secpath_exists(skb))
 		return 0;
@@ -224,6 +328,7 @@ static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 	if (!xi)
 		return 1;
 
+	link = skb->dev->ifindex;
 	dev = xi->dev;
 	skb->dev = dev;
 
@@ -254,6 +359,17 @@ static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 	}
 
 	xfrmi_scrub_packet(skb, xnet);
+	if (xi->p.collect_md) {
+		struct metadata_dst *md_dst;
+
+		md_dst = metadata_dst_alloc(0, METADATA_XFRM, GFP_ATOMIC);
+		if (!md_dst)
+			return -ENOMEM;
+
+		md_dst->u.xfrm_info.if_id = x->if_id;
+		md_dst->u.xfrm_info.link = link;
+		skb_dst_set(skb, (struct dst_entry *)md_dst);
+	}
 	dev_sw_netstats_rx_add(dev, skb->len);
 
 	return 0;
@@ -269,10 +385,23 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	struct net_device *tdev;
 	struct xfrm_state *x;
 	int err = -1;
+	u32 if_id;
 	int mtu;
 
+	if (xi->p.collect_md) {
+		struct xfrm_md_info *md_info = skb_xfrm_md_info(skb);
+
+		if (unlikely(!md_info))
+			return -EINVAL;
+
+		if_id = md_info->if_id;
+		fl->flowi_oif = md_info->link;
+	} else {
+		if_id = xi->p.if_id;
+	}
+
 	dst_hold(dst);
-	dst = xfrm_lookup_with_ifid(xi->net, dst, fl, NULL, 0, xi->p.if_id);
+	dst = xfrm_lookup_with_ifid(xi->net, dst, fl, NULL, 0, if_id);
 	if (IS_ERR(dst)) {
 		err = PTR_ERR(dst);
 		dst = NULL;
@@ -283,7 +412,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	if (!x)
 		goto tx_err_link_failure;
 
-	if (x->if_id != xi->p.if_id)
+	if (x->if_id != if_id)
 		goto tx_err_link_failure;
 
 	tdev = dst->dev;
@@ -633,6 +762,9 @@ static void xfrmi_netlink_parms(struct nlattr *data[],
 
 	if (data[IFLA_XFRM_IF_ID])
 		parms->if_id = nla_get_u32(data[IFLA_XFRM_IF_ID]);
+
+	if (data[IFLA_XFRM_COLLECT_METADATA])
+		parms->collect_md = true;
 }
 
 static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
@@ -645,14 +777,27 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
 	int err;
 
 	xfrmi_netlink_parms(data, &p);
-	if (!p.if_id) {
-		NL_SET_ERR_MSG(extack, "if_id must be non zero");
-		return -EINVAL;
-	}
+	if (p.collect_md) {
+		struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
 
-	xi = xfrmi_locate(net, &p);
-	if (xi)
-		return -EEXIST;
+		if (p.link || p.if_id) {
+			NL_SET_ERR_MSG(extack, "link and if_id must be zero");
+			return -EINVAL;
+		}
+
+		if (rtnl_dereference(xfrmn->collect_md_xfrmi))
+			return -EEXIST;
+
+	} else {
+		if (!p.if_id) {
+			NL_SET_ERR_MSG(extack, "if_id must be non zero");
+			return -EINVAL;
+		}
+
+		xi = xfrmi_locate(net, &p);
+		if (xi)
+			return -EEXIST;
+	}
 
 	xi = netdev_priv(dev);
 	xi->p = p;
@@ -682,12 +827,22 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[],
 		return -EINVAL;
 	}
 
+	if (p.collect_md) {
+		NL_SET_ERR_MSG(extack, "collect_md can't be changed");
+		return -EINVAL;
+	}
+
 	xi = xfrmi_locate(net, &p);
 	if (!xi) {
 		xi = netdev_priv(dev);
 	} else {
 		if (xi->dev != dev)
 			return -EEXIST;
+		if (xi->p.collect_md) {
+			NL_SET_ERR_MSG(extack,
+				       "device can't be changed to collect_md");
+			return -EINVAL;
+		}
 	}
 
 	return xfrmi_update(xi, &p);
@@ -700,6 +855,8 @@ static size_t xfrmi_get_size(const struct net_device *dev)
 		nla_total_size(4) +
 		/* IFLA_XFRM_IF_ID */
 		nla_total_size(4) +
+		/* IFLA_XFRM_COLLECT_METADATA */
+		nla_total_size(0) +
 		0;
 }
 
@@ -709,7 +866,8 @@ static int xfrmi_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	struct xfrm_if_parms *parm = &xi->p;
 
 	if (nla_put_u32(skb, IFLA_XFRM_LINK, parm->link) ||
-	    nla_put_u32(skb, IFLA_XFRM_IF_ID, parm->if_id))
+	    nla_put_u32(skb, IFLA_XFRM_IF_ID, parm->if_id) ||
+	    (xi->p.collect_md && nla_put_flag(skb, IFLA_XFRM_COLLECT_METADATA)))
 		goto nla_put_failure;
 	return 0;
 
@@ -725,8 +883,10 @@ static struct net *xfrmi_get_link_net(const struct net_device *dev)
 }
 
 static const struct nla_policy xfrmi_policy[IFLA_XFRM_MAX + 1] = {
-	[IFLA_XFRM_LINK]	= { .type = NLA_U32 },
-	[IFLA_XFRM_IF_ID]	= { .type = NLA_U32 },
+	[IFLA_XFRM_UNSPEC]		= { .strict_start_type = IFLA_XFRM_COLLECT_METADATA },
+	[IFLA_XFRM_LINK]		= { .type = NLA_U32 },
+	[IFLA_XFRM_IF_ID]		= { .type = NLA_U32 },
+	[IFLA_XFRM_COLLECT_METADATA]	= { .type = NLA_FLAG },
 };
 
 static struct rtnl_link_ops xfrmi_link_ops __read_mostly = {
@@ -762,6 +922,9 @@ static void __net_exit xfrmi_exit_batch_net(struct list_head *net_exit_list)
 			     xip = &xi->next)
 				unregister_netdevice_queue(xi->dev, &list);
 		}
+		xi = rtnl_dereference(xfrmn->collect_md_xfrmi);
+		if (xi)
+			unregister_netdevice_queue(xi->dev, &list);
 	}
 	unregister_netdevice_many(&list);
 	rtnl_unlock();
@@ -999,6 +1162,8 @@ static int __init xfrmi_init(void)
 	if (err < 0)
 		goto rtnl_link_failed;
 
+	lwtunnel_encap_add_ops(&xfrmi_encap_ops, LWTUNNEL_ENCAP_XFRM);
+
 	xfrm_if_register_cb(&xfrm_if_cb);
 
 	return err;
@@ -1017,6 +1182,7 @@ pernet_dev_failed:
 static void __exit xfrmi_fini(void)
 {
 	xfrm_if_unregister_cb();
+	lwtunnel_encap_del_ops(&xfrmi_encap_ops, LWTUNNEL_ENCAP_XFRM);
 	rtnl_link_unregister(&xfrmi_link_ops);
 	xfrmi4_fini();
 	xfrmi6_fini();
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index cb40ff0ff28d..656045a87606 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -325,18 +325,22 @@ void ipcomp_destroy(struct xfrm_state *x)
 }
 EXPORT_SYMBOL_GPL(ipcomp_destroy);
 
-int ipcomp_init_state(struct xfrm_state *x)
+int ipcomp_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
 {
 	int err;
 	struct ipcomp_data *ipcd;
 	struct xfrm_algo_desc *calg_desc;
 
 	err = -EINVAL;
-	if (!x->calg)
+	if (!x->calg) {
+		NL_SET_ERR_MSG(extack, "Missing required compression algorithm");
 		goto out;
+	}
 
-	if (x->encap)
+	if (x->encap) {
+		NL_SET_ERR_MSG(extack, "IPComp is not compatible with encapsulation");
 		goto out;
+	}
 
 	err = -ENOMEM;
 	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index cc6ab79609e2..e392d8d05e0c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1889,7 +1889,7 @@ EXPORT_SYMBOL(xfrm_policy_walk_done);
  */
 static int xfrm_policy_match(const struct xfrm_policy *pol,
 			     const struct flowi *fl,
-			     u8 type, u16 family, int dir, u32 if_id)
+			     u8 type, u16 family, u32 if_id)
 {
 	const struct xfrm_selector *sel = &pol->selector;
 	int ret = -ESRCH;
@@ -2014,7 +2014,7 @@ static struct xfrm_policy *
 __xfrm_policy_eval_candidates(struct hlist_head *chain,
 			      struct xfrm_policy *prefer,
 			      const struct flowi *fl,
-			      u8 type, u16 family, int dir, u32 if_id)
+			      u8 type, u16 family, u32 if_id)
 {
 	u32 priority = prefer ? prefer->priority : ~0u;
 	struct xfrm_policy *pol;
@@ -2028,7 +2028,7 @@ __xfrm_policy_eval_candidates(struct hlist_head *chain,
 		if (pol->priority > priority)
 			break;
 
-		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
+		err = xfrm_policy_match(pol, fl, type, family, if_id);
 		if (err) {
 			if (err != -ESRCH)
 				return ERR_PTR(err);
@@ -2053,7 +2053,7 @@ static struct xfrm_policy *
 xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
 			    struct xfrm_policy *prefer,
 			    const struct flowi *fl,
-			    u8 type, u16 family, int dir, u32 if_id)
+			    u8 type, u16 family, u32 if_id)
 {
 	struct xfrm_policy *tmp;
 	int i;
@@ -2061,8 +2061,7 @@ xfrm_policy_eval_candidates(struct xfrm_pol_inexact_candidates *cand,
 	for (i = 0; i < ARRAY_SIZE(cand->res); i++) {
 		tmp = __xfrm_policy_eval_candidates(cand->res[i],
 						    prefer,
-						    fl, type, family, dir,
-						    if_id);
+						    fl, type, family, if_id);
 		if (!tmp)
 			continue;
 
@@ -2101,7 +2100,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 
 	ret = NULL;
 	hlist_for_each_entry_rcu(pol, chain, bydst) {
-		err = xfrm_policy_match(pol, fl, type, family, dir, if_id);
+		err = xfrm_policy_match(pol, fl, type, family, if_id);
 		if (err) {
 			if (err == -ESRCH)
 				continue;
@@ -2120,7 +2119,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 		goto skip_inexact;
 
 	pol = xfrm_policy_eval_candidates(&cand, ret, fl, type,
-					  family, dir, if_id);
+					  family, if_id);
 	if (pol) {
 		ret = pol;
 		if (IS_ERR(pol))
@@ -3516,17 +3515,17 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 	int xerr_idx = -1;
 	const struct xfrm_if_cb *ifcb;
 	struct sec_path *sp;
-	struct xfrm_if *xi;
 	u32 if_id = 0;
 
 	rcu_read_lock();
 	ifcb = xfrm_if_get_cb();
 
 	if (ifcb) {
-		xi = ifcb->decode_session(skb, family);
-		if (xi) {
-			if_id = xi->p.if_id;
-			net = xi->net;
+		struct xfrm_if_decode_session_result r;
+
+		if (ifcb->decode_session(skb, family, &r)) {
+			if_id = r.if_id;
+			net = r.net;
 		}
 	}
 	rcu_read_unlock();
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 9277d81b344c..9f4d42eb090f 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -766,18 +766,22 @@ int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
 }
 #endif
 
-int xfrm_init_replay(struct xfrm_state *x)
+int xfrm_init_replay(struct xfrm_state *x, struct netlink_ext_ack *extack)
 {
 	struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
 
 	if (replay_esn) {
 		if (replay_esn->replay_window >
-		    replay_esn->bmp_len * sizeof(__u32) * 8)
+		    replay_esn->bmp_len * sizeof(__u32) * 8) {
+			NL_SET_ERR_MSG(extack, "ESN replay window is too large for the chosen bitmap size");
 			return -EINVAL;
+		}
 
 		if (x->props.flags & XFRM_STATE_ESN) {
-			if (replay_esn->replay_window == 0)
+			if (replay_esn->replay_window == 0) {
+				NL_SET_ERR_MSG(extack, "ESN replay window must be > 0");
 				return -EINVAL;
+			}
 			x->repl_mode = XFRM_REPLAY_MODE_ESN;
 		} else {
 			x->repl_mode = XFRM_REPLAY_MODE_BMP;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 91c32a3b6924..81df34b3da6e 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2611,7 +2611,8 @@ u32 xfrm_state_mtu(struct xfrm_state *x, int mtu)
 }
 EXPORT_SYMBOL_GPL(xfrm_state_mtu);
 
-int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
+int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload,
+		      struct netlink_ext_ack *extack)
 {
 	const struct xfrm_mode *inner_mode;
 	const struct xfrm_mode *outer_mode;
@@ -2626,12 +2627,16 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 
 	if (x->sel.family != AF_UNSPEC) {
 		inner_mode = xfrm_get_mode(x->props.mode, x->sel.family);
-		if (inner_mode == NULL)
+		if (inner_mode == NULL) {
+			NL_SET_ERR_MSG(extack, "Requested mode not found");
 			goto error;
+		}
 
 		if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
-		    family != x->sel.family)
+		    family != x->sel.family) {
+			NL_SET_ERR_MSG(extack, "Only tunnel modes can accommodate a change of family");
 			goto error;
+		}
 
 		x->inner_mode = *inner_mode;
 	} else {
@@ -2639,11 +2644,15 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 		int iafamily = AF_INET;
 
 		inner_mode = xfrm_get_mode(x->props.mode, x->props.family);
-		if (inner_mode == NULL)
+		if (inner_mode == NULL) {
+			NL_SET_ERR_MSG(extack, "Requested mode not found");
 			goto error;
+		}
 
-		if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL))
+		if (!(inner_mode->flags & XFRM_MODE_FLAG_TUNNEL)) {
+			NL_SET_ERR_MSG(extack, "Only tunnel modes can accommodate an AF_UNSPEC selector");
 			goto error;
+		}
 
 		x->inner_mode = *inner_mode;
 
@@ -2658,24 +2667,27 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
 	}
 
 	x->type = xfrm_get_type(x->id.proto, family);
-	if (x->type == NULL)
+	if (x->type == NULL) {
+		NL_SET_ERR_MSG(extack, "Requested type not found");
 		goto error;
+	}
 
 	x->type_offload = xfrm_get_type_offload(x->id.proto, family, offload);
 
-	err = x->type->init_state(x);
+	err = x->type->init_state(x, extack);
 	if (err)
 		goto error;
 
 	outer_mode = xfrm_get_mode(x->props.mode, family);
 	if (!outer_mode) {
+		NL_SET_ERR_MSG(extack, "Requested mode not found");
 		err = -EPROTONOSUPPORT;
 		goto error;
 	}
 
 	x->outer_mode = *outer_mode;
 	if (init_replay) {
-		err = xfrm_init_replay(x);
+		err = xfrm_init_replay(x, extack);
 		if (err)
 			goto error;
 	}
@@ -2690,7 +2702,7 @@ int xfrm_init_state(struct xfrm_state *x)
 {
 	int err;
 
-	err = __xfrm_init_state(x, true, false);
+	err = __xfrm_init_state(x, true, false, NULL);
 	if (!err)
 		x->km.state = XFRM_STATE_VALID;
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 2ff017117730..e73f9efc54c1 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -35,7 +35,8 @@
 #endif
 #include <asm/unaligned.h>
 
-static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
+static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type,
+			  struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[type];
 	struct xfrm_algo *algp;
@@ -44,8 +45,10 @@ static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
 		return 0;
 
 	algp = nla_data(rt);
-	if (nla_len(rt) < (int)xfrm_alg_len(algp))
+	if (nla_len(rt) < (int)xfrm_alg_len(algp)) {
+		NL_SET_ERR_MSG(extack, "Invalid AUTH/CRYPT/COMP attribute length");
 		return -EINVAL;
+	}
 
 	switch (type) {
 	case XFRMA_ALG_AUTH:
@@ -54,6 +57,7 @@ static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
 		break;
 
 	default:
+		NL_SET_ERR_MSG(extack, "Invalid algorithm attribute type");
 		return -EINVAL;
 	}
 
@@ -61,7 +65,8 @@ static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
 	return 0;
 }
 
-static int verify_auth_trunc(struct nlattr **attrs)
+static int verify_auth_trunc(struct nlattr **attrs,
+			     struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_ALG_AUTH_TRUNC];
 	struct xfrm_algo_auth *algp;
@@ -70,14 +75,16 @@ static int verify_auth_trunc(struct nlattr **attrs)
 		return 0;
 
 	algp = nla_data(rt);
-	if (nla_len(rt) < (int)xfrm_alg_auth_len(algp))
+	if (nla_len(rt) < (int)xfrm_alg_auth_len(algp)) {
+		NL_SET_ERR_MSG(extack, "Invalid AUTH_TRUNC attribute length");
 		return -EINVAL;
+	}
 
 	algp->alg_name[sizeof(algp->alg_name) - 1] = '\0';
 	return 0;
 }
 
-static int verify_aead(struct nlattr **attrs)
+static int verify_aead(struct nlattr **attrs, struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_ALG_AEAD];
 	struct xfrm_algo_aead *algp;
@@ -86,8 +93,10 @@ static int verify_aead(struct nlattr **attrs)
 		return 0;
 
 	algp = nla_data(rt);
-	if (nla_len(rt) < (int)aead_len(algp))
+	if (nla_len(rt) < (int)aead_len(algp)) {
+		NL_SET_ERR_MSG(extack, "Invalid AEAD attribute length");
 		return -EINVAL;
+	}
 
 	algp->alg_name[sizeof(algp->alg_name) - 1] = '\0';
 	return 0;
@@ -102,7 +111,7 @@ static void verify_one_addr(struct nlattr **attrs, enum xfrm_attr_type_t type,
 		*addrp = nla_data(rt);
 }
 
-static inline int verify_sec_ctx_len(struct nlattr **attrs)
+static inline int verify_sec_ctx_len(struct nlattr **attrs, struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_SEC_CTX];
 	struct xfrm_user_sec_ctx *uctx;
@@ -112,42 +121,59 @@ static inline int verify_sec_ctx_len(struct nlattr **attrs)
 
 	uctx = nla_data(rt);
 	if (uctx->len > nla_len(rt) ||
-	    uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len))
+	    uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len)) {
+		NL_SET_ERR_MSG(extack, "Invalid security context length");
 		return -EINVAL;
+	}
 
 	return 0;
 }
 
 static inline int verify_replay(struct xfrm_usersa_info *p,
-				struct nlattr **attrs)
+				struct nlattr **attrs,
+				struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_REPLAY_ESN_VAL];
 	struct xfrm_replay_state_esn *rs;
 
-	if (!rt)
-		return (p->flags & XFRM_STATE_ESN) ? -EINVAL : 0;
+	if (!rt) {
+		if (p->flags & XFRM_STATE_ESN) {
+			NL_SET_ERR_MSG(extack, "Missing required attribute for ESN");
+			return -EINVAL;
+		}
+		return 0;
+	}
 
 	rs = nla_data(rt);
 
-	if (rs->bmp_len > XFRMA_REPLAY_ESN_MAX / sizeof(rs->bmp[0]) / 8)
+	if (rs->bmp_len > XFRMA_REPLAY_ESN_MAX / sizeof(rs->bmp[0]) / 8) {
+		NL_SET_ERR_MSG(extack, "ESN bitmap length must be <= 128");
 		return -EINVAL;
+	}
 
 	if (nla_len(rt) < (int)xfrm_replay_state_esn_len(rs) &&
-	    nla_len(rt) != sizeof(*rs))
+	    nla_len(rt) != sizeof(*rs)) {
+		NL_SET_ERR_MSG(extack, "ESN attribute is too short to fit the full bitmap length");
 		return -EINVAL;
+	}
 
 	/* As only ESP and AH support ESN feature. */
-	if ((p->id.proto != IPPROTO_ESP) && (p->id.proto != IPPROTO_AH))
+	if ((p->id.proto != IPPROTO_ESP) && (p->id.proto != IPPROTO_AH)) {
+		NL_SET_ERR_MSG(extack, "ESN only supported for ESP and AH");
 		return -EINVAL;
+	}
 
-	if (p->replay_window != 0)
+	if (p->replay_window != 0) {
+		NL_SET_ERR_MSG(extack, "ESN not compatible with legacy replay_window");
 		return -EINVAL;
+	}
 
 	return 0;
 }
 
 static int verify_newsa_info(struct xfrm_usersa_info *p,
-			     struct nlattr **attrs)
+			     struct nlattr **attrs,
+			     struct netlink_ext_ack *extack)
 {
 	int err;
 
@@ -161,10 +187,12 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 		break;
 #else
 		err = -EAFNOSUPPORT;
+		NL_SET_ERR_MSG(extack, "IPv6 support disabled");
 		goto out;
 #endif
 
 	default:
+		NL_SET_ERR_MSG(extack, "Invalid address family");
 		goto out;
 	}
 
@@ -173,65 +201,98 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 		break;
 
 	case AF_INET:
-		if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
+		if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32) {
+			NL_SET_ERR_MSG(extack, "Invalid prefix length in selector (must be <= 32 for IPv4)");
 			goto out;
+		}
 
 		break;
 
 	case AF_INET6:
 #if IS_ENABLED(CONFIG_IPV6)
-		if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128)
+		if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128) {
+			NL_SET_ERR_MSG(extack, "Invalid prefix length in selector (must be <= 128 for IPv6)");
 			goto out;
+		}
 
 		break;
 #else
+		NL_SET_ERR_MSG(extack, "IPv6 support disabled");
 		err = -EAFNOSUPPORT;
 		goto out;
 #endif
 
 	default:
+		NL_SET_ERR_MSG(extack, "Invalid address family in selector");
 		goto out;
 	}
 
 	err = -EINVAL;
 	switch (p->id.proto) {
 	case IPPROTO_AH:
-		if ((!attrs[XFRMA_ALG_AUTH]	&&
-		     !attrs[XFRMA_ALG_AUTH_TRUNC]) ||
-		    attrs[XFRMA_ALG_AEAD]	||
+		if (!attrs[XFRMA_ALG_AUTH]	&&
+		    !attrs[XFRMA_ALG_AUTH_TRUNC]) {
+			NL_SET_ERR_MSG(extack, "Missing required attribute for AH: AUTH_TRUNC or AUTH");
+			goto out;
+		}
+
+		if (attrs[XFRMA_ALG_AEAD]	||
 		    attrs[XFRMA_ALG_CRYPT]	||
 		    attrs[XFRMA_ALG_COMP]	||
-		    attrs[XFRMA_TFCPAD])
+		    attrs[XFRMA_TFCPAD]) {
+			NL_SET_ERR_MSG(extack, "Invalid attributes for AH: AEAD, CRYPT, COMP, TFCPAD");
 			goto out;
+		}
 		break;
 
 	case IPPROTO_ESP:
-		if (attrs[XFRMA_ALG_COMP])
+		if (attrs[XFRMA_ALG_COMP]) {
+			NL_SET_ERR_MSG(extack, "Invalid attribute for ESP: COMP");
 			goto out;
+		}
+
 		if (!attrs[XFRMA_ALG_AUTH] &&
 		    !attrs[XFRMA_ALG_AUTH_TRUNC] &&
 		    !attrs[XFRMA_ALG_CRYPT] &&
-		    !attrs[XFRMA_ALG_AEAD])
+		    !attrs[XFRMA_ALG_AEAD]) {
+			NL_SET_ERR_MSG(extack, "Missing required attribute for ESP: at least one of AUTH, AUTH_TRUNC, CRYPT, AEAD");
 			goto out;
+		}
+
 		if ((attrs[XFRMA_ALG_AUTH] ||
 		     attrs[XFRMA_ALG_AUTH_TRUNC] ||
 		     attrs[XFRMA_ALG_CRYPT]) &&
-		    attrs[XFRMA_ALG_AEAD])
+		    attrs[XFRMA_ALG_AEAD]) {
+			NL_SET_ERR_MSG(extack, "Invalid attribute combination for ESP: AEAD can't be used with AUTH, AUTH_TRUNC, CRYPT");
 			goto out;
+		}
+
 		if (attrs[XFRMA_TFCPAD] &&
-		    p->mode != XFRM_MODE_TUNNEL)
+		    p->mode != XFRM_MODE_TUNNEL) {
+			NL_SET_ERR_MSG(extack, "TFC padding can only be used in tunnel mode");
 			goto out;
+		}
 		break;
 
 	case IPPROTO_COMP:
-		if (!attrs[XFRMA_ALG_COMP]	||
-		    attrs[XFRMA_ALG_AEAD]	||
+		if (!attrs[XFRMA_ALG_COMP]) {
+			NL_SET_ERR_MSG(extack, "Missing required attribute for COMP: COMP");
+			goto out;
+		}
+
+		if (attrs[XFRMA_ALG_AEAD]	||
 		    attrs[XFRMA_ALG_AUTH]	||
 		    attrs[XFRMA_ALG_AUTH_TRUNC]	||
 		    attrs[XFRMA_ALG_CRYPT]	||
-		    attrs[XFRMA_TFCPAD]		||
-		    (ntohl(p->id.spi) >= 0x10000))
+		    attrs[XFRMA_TFCPAD]) {
+			NL_SET_ERR_MSG(extack, "Invalid attributes for COMP: AEAD, AUTH, AUTH_TRUNC, CRYPT, TFCPAD");
 			goto out;
+		}
+
+		if (ntohl(p->id.spi) >= 0x10000) {
+			NL_SET_ERR_MSG(extack, "SPI is too large for COMP (must be < 0x10000)");
+			goto out;
+		}
 		break;
 
 #if IS_ENABLED(CONFIG_IPV6)
@@ -244,29 +305,36 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 		    attrs[XFRMA_ALG_CRYPT]	||
 		    attrs[XFRMA_ENCAP]		||
 		    attrs[XFRMA_SEC_CTX]	||
-		    attrs[XFRMA_TFCPAD]		||
-		    !attrs[XFRMA_COADDR])
+		    attrs[XFRMA_TFCPAD]) {
+			NL_SET_ERR_MSG(extack, "Invalid attributes for DSTOPTS/ROUTING");
 			goto out;
+		}
+
+		if (!attrs[XFRMA_COADDR]) {
+			NL_SET_ERR_MSG(extack, "Missing required COADDR attribute for DSTOPTS/ROUTING");
+			goto out;
+		}
 		break;
 #endif
 
 	default:
+		NL_SET_ERR_MSG(extack, "Unsupported protocol");
 		goto out;
 	}
 
-	if ((err = verify_aead(attrs)))
+	if ((err = verify_aead(attrs, extack)))
 		goto out;
-	if ((err = verify_auth_trunc(attrs)))
+	if ((err = verify_auth_trunc(attrs, extack)))
 		goto out;
-	if ((err = verify_one_alg(attrs, XFRMA_ALG_AUTH)))
+	if ((err = verify_one_alg(attrs, XFRMA_ALG_AUTH, extack)))
 		goto out;