6 files changed, 51 insertions, 30 deletions

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index c215be70cac0..ace8daca5c83 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -325,14 +325,34 @@ void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
         kfree_skb(skb);
 }
 
-static void ip6_datagram_prepare_pktinfo_errqueue(struct sk_buff *skb)
+/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
+ *
+ * At one point, excluding local errors was a quick test to identify icmp/icmp6
+ * errors. This is no longer true, but the test remained, so the v6 stack,
+ * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
+ *
+ * Timestamp code paths do not initialize the fields expected by cmsg:
+ * the PKTINFO fields in skb->cb[]. Fill those in here.
+ */
+static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
+                                      struct sock_exterr_skb *serr)
 {
-        int ifindex = skb->dev ? skb->dev->ifindex : -1;
+        if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
+            serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
+                return true;
+
+        if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
+                return false;
+
+        if (!skb->dev)
+                return false;
 
         if (skb->protocol == htons(ETH_P_IPV6))
-                IP6CB(skb)->iif = ifindex;
+                IP6CB(skb)->iif = skb->dev->ifindex;
         else
-                PKTINFO_SKB_CB(skb)->ipi_ifindex = ifindex;
+                PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
+
+        return true;
 }
 
 /*
@@ -369,7 +389,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 
         serr = SKB_EXT_ERR(skb);
 
-        if (sin && skb->len) {
+        if (sin && serr->port) {
                 const unsigned char *nh = skb_network_header(skb);
                 sin->sin6_family = AF_INET6;
                 sin->sin6_flowinfo = 0;
@@ -394,14 +414,11 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
         sin = &errhdr.offender;
         memset(sin, 0, sizeof(*sin));
-        if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL && skb->len) {
+
+        if (ip6_datagram_support_cmsg(skb, serr)) {
                 sin->sin6_family = AF_INET6;
-                if (np->rxopt.all) {
-                        if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
-                            serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6)
-                                ip6_datagram_prepare_pktinfo_errqueue(skb);
+                if (np->rxopt.all)
                         ip6_datagram_recv_common_ctl(sk, msg, skb);
-                }
                 if (skb->protocol == htons(ETH_P_IPV6)) {
                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
                         if (np->rxopt.all)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 0a04a37305d5..7e80b61b51ff 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -318,6 +318,7 @@ static int ip6_forward_proxy_check(struct sk_buff *skb)
 
 static inline int ip6_forward_finish(struct sk_buff *skb)
 {
+        skb_sender_cpu_clear(skb);
         return dst_output(skb);
 }
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 266a264ec212..ddd94eca19b3 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -314,7 +314,7 @@ out:
  *   Create tunnel matching given parameters.
  *
  * Return:
- *   created tunnel or NULL
+ *   created tunnel or error pointer
  **/
 
 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
@@ -322,7 +322,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
         struct net_device *dev;
         struct ip6_tnl *t;
         char name[IFNAMSIZ];
-        int err;
+        int err = -ENOMEM;
 
         if (p->name[0])
                 strlcpy(name, p->name, IFNAMSIZ);
@@ -348,7 +348,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 failed_free:
         ip6_dev_free(dev);
 failed:
-        return NULL;
+        return ERR_PTR(err);
 }
 
 /**
@@ -362,7 +362,7 @@ failed:
  *   tunnel device is created and registered for use.
  *
  * Return:
- *   matching tunnel or NULL
+ *   matching tunnel or error pointer
  **/
 
 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
@@ -380,13 +380,13 @@ static struct ip6_tnl *ip6_tnl_locate(struct net *net,
                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
                     ipv6_addr_equal(remote, &t->parms.raddr)) {
                         if (create)
-                                return NULL;
+                                return ERR_PTR(-EEXIST);
 
                         return t;
                 }
         }
         if (!create)
-                return NULL;
+                return ERR_PTR(-ENODEV);
         return ip6_tnl_create(net, p);
 }
 
@@ -1420,7 +1420,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                         }
                         ip6_tnl_parm_from_user(&p1, &p);
                         t = ip6_tnl_locate(net, &p1, 0);
-                        if (t == NULL)
+                        if (IS_ERR(t))
                                 t = netdev_priv(dev);
                 } else {
                         memset(&p, 0, sizeof(p));
@@ -1445,7 +1445,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                 ip6_tnl_parm_from_user(&p1, &p);
                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
                 if (cmd == SIOCCHGTUNNEL) {
-                        if (t != NULL) {
+                        if (!IS_ERR(t)) {
                                 if (t->dev != dev) {
                                         err = -EEXIST;
                                         break;
@@ -1457,14 +1457,15 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                         else
                                 err = ip6_tnl_update(t, &p1);
                 }
-                if (t) {
+                if (!IS_ERR(t)) {
                         err = 0;
                         ip6_tnl_parm_to_user(&p, &t->parms);
                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
                                 err = -EFAULT;
 
-                } else
-                        err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+                } else {
+                        err = PTR_ERR(t);
+                }
                 break;
         case SIOCDELTUNNEL:
                 err = -EPERM;
@@ -1478,7 +1479,7 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                         err = -ENOENT;
                         ip6_tnl_parm_from_user(&p1, &p);
                         t = ip6_tnl_locate(net, &p1, 0);
-                        if (t == NULL)
+                        if (IS_ERR(t))
                                 break;
                         err = -EPERM;
                         if (t->dev == ip6n->fb_tnl_dev)
@@ -1672,12 +1673,13 @@ static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
                            struct nlattr *tb[], struct nlattr *data[])
 {
         struct net *net = dev_net(dev);
-        struct ip6_tnl *nt;
+        struct ip6_tnl *nt, *t;
 
         nt = netdev_priv(dev);
         ip6_tnl_netlink_parms(data, &nt->parms);
 
-        if (ip6_tnl_locate(net, &nt->parms, 0))
+        t = ip6_tnl_locate(net, &nt->parms, 0);
+        if (!IS_ERR(t))
                 return -EEXIST;
 
         return ip6_tnl_create2(dev);
@@ -1697,8 +1699,7 @@ static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
         ip6_tnl_netlink_parms(data, &p);
 
         t = ip6_tnl_locate(net, &p, 0);
-
-        if (t) {
+        if (!IS_ERR(t)) {
                 if (t->dev != dev)
                         return -EEXIST;
         } else
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c
index bd46f736f61d..a2dfff6ff227 100644
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -102,9 +102,10 @@ int ping_v6_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
         if (msg->msg_name) {
                 DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
-                if (msg->msg_namelen < sizeof(struct sockaddr_in6) ||
-                    u->sin6_family != AF_INET6) {
+                if (msg->msg_namelen < sizeof(*u))
                         return -EINVAL;
+                if (u->sin6_family != AF_INET6) {
+                        return -EAFNOSUPPORT;
                 }
                 if (sk->sk_bound_dev_if &&
                     sk->sk_bound_dev_if != u->sin6_scope_id) {
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index ca3f29b98ae5..010f8bd2d577 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -114,6 +114,7 @@ int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
                 return err;
 
         skb->ignore_df = 1;
+        skb->protocol = htons(ETH_P_IPV6);
 
         return x->outer_mode->output2(x, skb);
 }
@@ -122,7 +123,6 @@ EXPORT_SYMBOL(xfrm6_prepare_output);
 int xfrm6_output_finish(struct sk_buff *skb)
 {
         memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-        skb->protocol = htons(ETH_P_IPV6);
 
 #ifdef CONFIG_NETFILTER
         IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 48bf5a06847b..8d2d01b4800a 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -200,6 +200,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
 
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
                 case IPPROTO_MH:
+                        offset += ipv6_optlen(exthdr);
                         if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
                                 struct ip6_mh *mh;