Merge v7.1.5linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

17 files changed, 125 insertions, 55 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c9e5d3e48ab9..defa4277e783 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -913,7 +913,7 @@ static int addrconf_fixup_forwarding(const struct ctl_table *table, int *p, int
 
 	if (newf)
 		rt6_purge_dflt_routers(net);
-	return 1;
+	return 0;
 }
 
 static void addrconf_linkdown_change(struct net *net, __s32 newf)
@@ -955,11 +955,7 @@ static int addrconf_fixup_linkdown(const struct ctl_table *table, int *p, int ne
 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
 						     NETCONFA_IFINDEX_DEFAULT,
 						     net->ipv6.devconf_dflt);
-		rtnl_net_unlock(net);
-		return 0;
-	}
-
-	if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
+	} else if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
 		WRITE_ONCE(net->ipv6.devconf_dflt->ignore_routes_with_linkdown, newf);
 		addrconf_linkdown_change(net, newf);
 		if ((!newf) ^ (!old))
@@ -968,11 +964,21 @@ static int addrconf_fixup_linkdown(const struct ctl_table *table, int *p, int ne
 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
 						     NETCONFA_IFINDEX_ALL,
 						     net->ipv6.devconf_all);
+	} else {
+		if (!newf ^ !old) {
+			struct inet6_dev *idev = table->extra1;
+
+			inet6_netconf_notify_devconf(net,
+						     RTM_NEWNETCONF,
+						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
+						     idev->dev->ifindex,
+						     &idev->cnf);
+		}
 	}
 
 	rtnl_net_unlock(net);
 
-	return 1;
+	return 0;
 }
 
 #endif
@@ -2168,16 +2174,18 @@ void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp)
 	struct net *net = dev_net(idev->dev);
 	int max_addresses;
 
-	if (addrconf_dad_end(ifp)) {
+	spin_lock_bh(&ifp->lock);
+
+	if (ifp->state != INET6_IFADDR_STATE_DAD) {
+		spin_unlock_bh(&ifp->lock);
 		in6_ifa_put(ifp);
 		return;
 	}
+	ifp->state = INET6_IFADDR_STATE_POSTDAD;
 
 	net_info_ratelimited("%s: IPv6 duplicate address %pI6c used by %pM detected!\n",
 			     ifp->idev->dev->name, &ifp->addr, eth_hdr(skb)->h_source);
 
-	spin_lock_bh(&ifp->lock);
-
 	if (ifp->flags & IFA_F_STABLE_PRIVACY) {
 		struct in6_addr new_addr;
 		struct inet6_ifaddr *ifp2;
@@ -2225,6 +2233,11 @@ void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp)
 		in6_ifa_put(ifp2);
 lock_errdad:
 		spin_lock_bh(&ifp->lock);
+		if (ifp->state != INET6_IFADDR_STATE_POSTDAD) {
+			spin_unlock_bh(&ifp->lock);
+			in6_ifa_put(ifp);
+			return;
+		}
 	}
 
 errdad:
@@ -6355,6 +6368,8 @@ static int addrconf_sysctl_forward(const struct ctl_table *ctl, int write,
 	lctl.data = &val;
 
 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
 
 	if (write)
 		ret = addrconf_fixup_forwarding(ctl, valp, val);
@@ -6452,6 +6467,8 @@ static int addrconf_sysctl_disable(const struct ctl_table *ctl, int write,
 	lctl.data = &val;
 
 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
 
 	if (write)
 		ret = addrconf_disable_ipv6(ctl, valp, val);
@@ -6463,20 +6480,19 @@ static int addrconf_sysctl_disable(const struct ctl_table *ctl, int write,
 static int addrconf_sysctl_proxy_ndp(const struct ctl_table *ctl, int write,
 		void *buffer, size_t *lenp, loff_t *ppos)
 {
+	struct net *net = ctl->extra2;
 	int *valp = ctl->data;
-	int ret;
 	int old, new;
+	int ret;
+
+	if (write && !rtnl_net_trylock(net))
+		return restart_syscall();
 
 	old = *valp;
 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
 	new = *valp;
 
 	if (write && old != new) {
-		struct net *net = ctl->extra2;
-
-		if (!rtnl_net_trylock(net))
-			return restart_syscall();
-
 		if (valp == &net->ipv6.devconf_dflt->proxy_ndp) {
 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
 						     NETCONFA_PROXY_NEIGH,
@@ -6495,8 +6511,9 @@ static int addrconf_sysctl_proxy_ndp(const struct ctl_table *ctl, int write,
 						     idev->dev->ifindex,
 						     &idev->cnf);
 		}
-		rtnl_net_unlock(net);
 	}
+	if (write)
+		rtnl_net_unlock(net);
 
 	return ret;
 }
@@ -6654,6 +6671,8 @@ int addrconf_sysctl_ignore_routes_with_linkdown(const struct ctl_table *ctl,
 	lctl.data = &val;
 
 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
 
 	if (write)
 		ret = addrconf_fixup_linkdown(ctl, valp, val);
@@ -6748,6 +6767,8 @@ static int addrconf_sysctl_disable_policy(const struct ctl_table *ctl, int write
 	lctl = *ctl;
 	lctl.data = &val;
 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
 
 	if (write && (*valp != val))
 		ret = addrconf_disable_policy(ctl, valp, val);
diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c
index b9f6d892a566..cfb2c41634a0 100644
--- a/net/ipv6/ioam6_iptunnel.c
+++ b/net/ipv6/ioam6_iptunnel.c
@@ -35,7 +35,7 @@ struct ioam6_lwt_freq {
 };
 
 struct ioam6_lwt {
-	struct dst_entry null_dst;
+	struct rt6_info null_rt;
 	struct dst_cache cache;
 	struct ioam6_lwt_freq freq;
 	atomic_t pkt_cnt;
@@ -176,7 +176,7 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
 	 * it is stored in the cache. Then, +1/-1 each time we read the cache
 	 * and release it. Long story short, we're fine.
 	 */
-	dst_init(&ilwt->null_dst, NULL, NULL, DST_OBSOLETE_NONE, DST_NOCOUNT);
+	dst_init(&ilwt->null_rt.dst, NULL, NULL, DST_OBSOLETE_NONE, DST_NOCOUNT);
 
 	atomic_set(&ilwt->pkt_cnt, 0);
 	ilwt->freq.k = freq_k;
@@ -360,7 +360,7 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	/* This is how we notify that the destination does not change after
 	 * transformation and that we need to use orig_dst instead of the cache
 	 */
-	if (dst == &ilwt->null_dst) {
+	if (dst == &ilwt->null_rt.dst) {
 		dst_release(dst);
 
 		dst = orig_dst;
@@ -429,7 +429,7 @@ do_encap:
 		local_bh_disable();
 		if (orig_dst->lwtstate == dst->lwtstate)
 			dst_cache_set_ip6(&ilwt->cache,
-					  &ilwt->null_dst, &fl6.saddr);
+					  &ilwt->null_rt.dst, &fl6.saddr);
 		else
 			dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr);
 		local_bh_enable();
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index b897b3c5023b..414fc3c56736 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -637,12 +637,12 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 	};
 	const struct nlmsghdr *nlh = cb->nlh;
 	struct net *net = sock_net(skb->sk);
-	unsigned int e = 0, s_e;
 	struct hlist_head *head;
 	struct fib6_walker *w;
 	struct fib6_table *tb;
 	unsigned int h, s_h;
 	int err = 0;
+	u32 s_id;
 
 	rcu_read_lock();
 	if (cb->strict_check) {
@@ -702,23 +702,22 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	s_h = cb->args[0];
-	s_e = cb->args[1];
+	s_id = cb->args[1];
 
-	for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
-		e = 0;
+	for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_id = 0) {
 		head = &net->ipv6.fib_table_hash[h];
 		hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
-			if (e < s_e)
-				goto next;
+			if (s_id && tb->tb6_id != s_id)
+				continue;
+
+			s_id = 0;
+			cb->args[1] = tb->tb6_id;
 			err = fib6_dump_table(tb, skb, cb);
 			if (err != 0)
 				goto out;
-next:
-			e++;
 		}
 	}
 out:
-	cb->args[1] = e;
 	cb->args[0] = h;
 
 unlock:
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 365b4059eb20..8ebc99a299c9 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -2047,6 +2047,9 @@ static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 	struct __ip6_tnl_parm p;
 
+	if (!rtnl_dev_link_net_capable(dev, t->net))
+		return -EPERM;
+
 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
 	if (IS_ERR(t))
 		return PTR_ERR(t);
@@ -2266,6 +2269,9 @@ static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct __ip6_tnl_parm p;
 	struct ip6gre_net *ign;
 
+	if (!rtnl_dev_link_net_capable(dev, t->net))
+		return -EPERM;
+
 	ign = net_generic(t->net, ip6gre_net_id);
 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
 	if (IS_ERR(t))
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 9d1037ac082f..95da1f087294 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1850,6 +1850,13 @@ static int ip6_tnl_fill_forward_path(struct net_device_path_ctx *ctx,
 	struct dst_entry *dst;
 	int err;
 
+	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
+		/* encaplimit option is currently not supported is
+		 * sw-acceleration path.
+		 */
+		return -EOPNOTSUPP;
+	}
+
 	dst = ip6_route_output(dev_net(ctx->dev), NULL, &fl6);
 	if (!dst->error) {
 		path->type = DEV_PATH_TUN;
@@ -2102,6 +2109,9 @@ static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 	struct ip_tunnel_encap ipencap;
 
+	if (!rtnl_dev_link_net_capable(dev, net))
+		return -EPERM;
+
 	if (dev == ip6n->fb_tnl_dev) {
 		if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
 			/* iproute2 always sets TUNNEL_ENCAP_FLAG_CSUM6, so
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index d871cab6938d..ab94b3a4ba9c 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -1046,6 +1046,9 @@ static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct __ip6_tnl_parm p;
 	struct vti6_net *ip6n;
 
+	if (!rtnl_dev_link_net_capable(dev, net))
+		return -EPERM;
+
 	ip6n = net_generic(net, vti6_net_id);
 	if (dev == ip6n->fb_tnl_dev)
 		return -EINVAL;
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index d9b855d5191b..2a5e76a38002 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1080,8 +1080,10 @@ static void mld_gq_start_work(struct inet6_dev *idev)
 	mc_assert_locked(idev);
 
 	idev->mc_gq_running = 1;
-	if (!mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
-		in6_dev_hold(idev);
+	if (in6_dev_hold_safe(idev)) {
+		if (mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
+			in6_dev_put(idev);
+	}
 }
 
 static void mld_gq_stop_work(struct inet6_dev *idev)
@@ -1099,8 +1101,10 @@ static void mld_ifc_start_work(struct inet6_dev *idev, unsigned long delay)
 
 	mc_assert_locked(idev);
 
-	if (!mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
-		in6_dev_hold(idev);
+	if (in6_dev_hold_safe(idev)) {
+		if (mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
+			in6_dev_put(idev);
+	}
 }
 
 static void mld_ifc_stop_work(struct inet6_dev *idev)
@@ -1118,8 +1122,10 @@ static void mld_dad_start_work(struct inet6_dev *idev, unsigned long delay)
 
 	mc_assert_locked(idev);
 
-	if (!mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
-		in6_dev_hold(idev);
+	if (in6_dev_hold_safe(idev)) {
+		if (mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
+			in6_dev_put(idev);
+	}
 }
 
 static void mld_dad_stop_work(struct inet6_dev *idev)
@@ -1405,18 +1411,23 @@ static void mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
 void igmp6_event_query(struct sk_buff *skb)
 {
 	struct inet6_dev *idev = __in6_dev_get(skb->dev);
+	bool put = false;
 
 	if (!idev || idev->dead)
 		goto out;
 
 	spin_lock_bh(&idev->mc_query_lock);
-	if (skb_queue_len(&idev->mc_query_queue) < MLD_MAX_SKBS) {
+	if (skb_queue_len(&idev->mc_query_queue) < MLD_MAX_SKBS &&
+	    in6_dev_hold_safe(idev)) {
 		__skb_queue_tail(&idev->mc_query_queue, skb);
-		if (!mod_delayed_work(mld_wq, &idev->mc_query_work, 0))
-			in6_dev_hold(idev);
+		if (mod_delayed_work(mld_wq, &idev->mc_query_work, 0))
+			put = true;
 		skb = NULL;
 	}
 	spin_unlock_bh(&idev->mc_query_lock);
+
+	if (put)
+		in6_dev_put(idev);
 out:
 	kfree_skb(skb);
 }
@@ -1573,18 +1584,23 @@ static void mld_query_work(struct work_struct *work)
 void igmp6_event_report(struct sk_buff *skb)
 {
 	struct inet6_dev *idev = __in6_dev_get(skb->dev);
+	bool put = false;
 
 	if (!idev || idev->dead)
 		goto out;
 
 	spin_lock_bh(&idev->mc_report_lock);
-	if (skb_queue_len(&idev->mc_report_queue) < MLD_MAX_SKBS) {
+	if (skb_queue_len(&idev->mc_report_queue) < MLD_MAX_SKBS &&
+	    in6_dev_hold_safe(idev)) {
 		__skb_queue_tail(&idev->mc_report_queue, skb);
-		if (!mod_delayed_work(mld_wq, &idev->mc_report_work, 0))
-			in6_dev_hold(idev);
+		if (mod_delayed_work(mld_wq, &idev->mc_report_work, 0))
+			put = true;
 		skb = NULL;
 	}
 	spin_unlock_bh(&idev->mc_report_lock);
+
+	if (put)
+		in6_dev_put(idev);
 out:
 	kfree_skb(skb);
 }
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index e7ad13c5bd26..f867ec8d3d90 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -967,10 +967,8 @@ out:
 	return reason;
 }
 
-static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
+static int accept_untracked_na(struct inet6_dev *idev, struct in6_addr *saddr)
 {
-	struct inet6_dev *idev = __in6_dev_get(dev);
-
 	switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
 	case 0: /* Don't accept untracked na (absent in neighbor cache) */
 		return 0;
@@ -980,7 +978,7 @@ static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
 		 * same subnet as an address configured on the interface that
 		 * received the na
 		 */
-		return !!ipv6_chk_prefix(saddr, dev);
+		return !!ipv6_chk_prefix(saddr, idev->dev);
 	default:
 		return 0;
 	}
@@ -1078,7 +1076,7 @@ static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
 	 */
 	new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
 	if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
-		if (accept_untracked_na(dev, saddr)) {
+		if (accept_untracked_na(idev, saddr)) {
 			neigh = neigh_create(&nd_tbl, &msg->target, dev);
 			new_state = NUD_STALE;
 		}
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 6d80f85e55fa..a7025ec87035 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -120,7 +120,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 	ktime_t tstamp = skb->tstamp;
 	struct ip6_frag_state state;
 	u8 *prevhdr, nexthdr = 0;
-	unsigned int mtu, hlen;
+	unsigned int mtu, hlen, nexthdr_offset;
 	int hroom, err = 0;
 	__be32 frag_id;
 
@@ -129,6 +129,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 		goto blackhole;
 	hlen = err;
 	nexthdr = *prevhdr;
+	nexthdr_offset = prevhdr - skb_network_header(skb);
 
 	mtu = skb->dev->mtu;
 	if (frag_max_size > mtu ||
@@ -147,6 +148,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 	    (err = skb_checksum_help(skb)))
 		goto blackhole;
 
+	prevhdr = skb_network_header(skb) + nexthdr_offset;
 	hroom = LL_RESERVED_SPACE(skb->dev);
 	if (skb_has_frag_list(skb)) {
 		unsigned int first_len = skb_pagelen(skb);
diff --git a/net/ipv6/netfilter/ip6t_ah.c b/net/ipv6/netfilter/ip6t_ah.c
index 70da2f2ce064..1258783ed876 100644
--- a/net/ipv6/netfilter/ip6t_ah.c
+++ b/net/ipv6/netfilter/ip6t_ah.c
@@ -56,6 +56,11 @@ static bool ah_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 	}
 
 	hdrlen = ipv6_authlen(ah);
+	if (skb->len - ptr < hdrlen) {
+		/* Packet smaller than its length field */
+		par->hotdrop = true;
+		return false;
+	}
 
 	pr_debug("IPv6 AH LEN %u %u ", hdrlen, ah->hdrlen);
 	pr_debug("RES %04X ", ah->reserved);
diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c
index 450dd53846a2..6d1a5d2026a6 100644
--- a/net/ipv6/netfilter/ip6t_hbh.c
+++ b/net/ipv6/netfilter/ip6t_hbh.c
@@ -75,6 +75,7 @@ hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 	hdrlen = ipv6_optlen(oh);
 	if (skb->len - ptr < hdrlen) {
 		/* Packet smaller than it's length field */
+		par->hotdrop = true;
 		return false;
 	}
 
diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c
index 5561bd9cea81..278b52752f36 100644
--- a/net/ipv6/netfilter/ip6t_rt.c
+++ b/net/ipv6/netfilter/ip6t_rt.c
@@ -56,7 +56,8 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 
 	hdrlen = ipv6_optlen(rh);
 	if (skb->len - ptr < hdrlen) {
-		/* Pcket smaller than its length field */
+		/* Packet smaller than its length field */
+		par->hotdrop = true;
 		return false;
 	}
 
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 7edca05dbfc9..599c49bf0a0a 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -348,7 +348,8 @@ static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb,
 	skb_network_header(skb)[fq->nhoffset] = skb_transport_header(skb)[0];
 	memmove(skb->head + sizeof(struct frag_hdr), skb->head,
 		(skb->data - skb->head) - sizeof(struct frag_hdr));
-	skb->mac_header += sizeof(struct frag_hdr);
+	if (skb_mac_header_was_set(skb))
+		skb->mac_header += sizeof(struct frag_hdr);
 	skb->network_header += sizeof(struct frag_hdr);
 
 	skb_reset_transport_header(skb);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 636f0120d7e3..88b46967bb67 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3275,11 +3275,11 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst)
 	/*
 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
-	 * IPV6_MAXPLEN is also valid and means: "any MSS,
-	 * rely only on pmtu discovery"
+	 * Limit the default MSS to GSO_BY_FRAGS - 1 to avoid
+	 * collision with the GSO_BY_FRAGS magic value (0xFFFF).
 	 */
 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
-		mtu = IPV6_MAXPLEN;
+		mtu = min_t(unsigned int, IPV6_MAXPLEN, GSO_BY_FRAGS - 1);
 	return mtu;
 }
 
@@ -5053,6 +5053,9 @@ static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
 		struct inet6_dev *idev = __in6_dev_get(arg->dev);
 		u32 mtu = f6i->fib6_pmtu;
 
+		if (!idev)
+			return 0;
+
 		if (mtu >= arg->mtu ||
 		    (mtu < arg->mtu && mtu == idev->cnf.mtu6))
 			fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index 1c3ad25700c4..62a7eb779202 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -29,6 +29,9 @@ bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced)
 	int max_last_entry;
 	int trailing;
 
+	if (len < sizeof(*srh))
+		return false;
+
 	if (srh->type != IPV6_SRCRT_TYPE_4)
 		return false;
 
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index b41e231a669b..34db8b886bd2 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1611,6 +1611,9 @@ static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
 	__u32 fwmark = t->fwmark;
 	int err;
 
+	if (!rtnl_dev_link_net_capable(dev, net))
+		return -EPERM;
+
 	if (dev == sitn->fb_tunnel_dev)
 		return -EINVAL;
 
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index 699a001ac166..89d0443b5307 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -71,8 +71,6 @@ int xfrm6_transport_finish(struct sk_buff *skb, int async)
 	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
 		dev_net(dev), NULL, skb, dev, NULL,
 		xfrm6_transport_finish2);
-	if (async)
-		dev_put(dev);
 	return 0;
 }