Merge branch 'gso_encap_fixes'

Florian Westphal says:

====================
net: minor gso encapsulation fixes

The following series fixes a minor bug in the gso segmentation handlers
when encapsulation offload is used.

Theoretically this could cause kernel panic when the stack tries
to software-segment such a GRE offload packet, but it looks like there
is only one affected call site (tbf scheduler) and it handles NULL
return value.

I've included a followup patch to add IS_ERR_OR_NULL checks where needed.

While looking into this, I also found that size computation of the individual
segments is incorrect if skb->encapsulation is set.

Please see individual patches for delta vs. v1.
====================

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

10 files changed, 21 insertions, 10 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 61059a05ec95..c16615bfb61e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4070,15 +4070,22 @@ EXPORT_SYMBOL_GPL(skb_scrub_packet);
 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
 {
         const struct skb_shared_info *shinfo = skb_shinfo(skb);
+        unsigned int thlen = 0;
 
-        if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
-                return tcp_hdrlen(skb) + shinfo->gso_size;
+        if (skb->encapsulation) {
+                thlen = skb_inner_transport_header(skb) -
+                        skb_transport_header(skb);
 
+                if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+                        thlen += inner_tcp_hdrlen(skb);
+        } else if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
+                thlen = tcp_hdrlen(skb);
+        }
         /* UFO sets gso_size to the size of the fragmentation
          * payload, i.e. the size of the L4 (UDP) header is already
          * accounted for.
          */
-        return shinfo->gso_size;
+        return thlen + shinfo->gso_size;
 }
 EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
 
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 92db7a69f2b9..8b7fe5b03906 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1246,7 +1246,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 
         encap = SKB_GSO_CB(skb)->encap_level > 0;
         if (encap)
-                features = skb->dev->hw_enc_features & netif_skb_features(skb);
+                features &= skb->dev->hw_enc_features;
         SKB_GSO_CB(skb)->encap_level += ihl;
 
         skb_reset_transport_header(skb);
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index ccda09628de7..f6e345c0bc23 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -68,7 +68,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
         skb->mac_len = skb_inner_network_offset(skb);
 
         /* segment inner packet. */
-        enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
+        enc_features = skb->dev->hw_enc_features & features;
         segs = skb_mac_gso_segment(skb, enc_features);
         if (IS_ERR_OR_NULL(segs)) {
                 skb_gso_error_unwind(skb, protocol, ghl, mac_offset, mac_len);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 88e5ef2c7f51..bc6471d4abcd 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -231,7 +231,7 @@ static int ip_finish_output_gso(struct sk_buff *skb)
          */
         features = netif_skb_features(skb);
         segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
-        if (IS_ERR(segs)) {
+        if (IS_ERR_OR_NULL(segs)) {
                 kfree_skb(skb);
                 return -ENOMEM;
         }
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 507310ef4b56..6480cea7aa53 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -58,7 +58,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
                 skb->encap_hdr_csum = 1;
 
         /* segment inner packet. */
-        enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
+        enc_features = skb->dev->hw_enc_features & features;
         segs = gso_inner_segment(skb, enc_features);
         if (IS_ERR_OR_NULL(segs)) {
                 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 91014d32488d..a071563a7e6e 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -90,7 +90,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 
         encap = SKB_GSO_CB(skb)->encap_level > 0;
         if (encap)
-                features = skb->dev->hw_enc_features & netif_skb_features(skb);
+                features &= skb->dev->hw_enc_features;
         SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
 
         ipv6h = ipv6_hdr(skb);
diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index e28ed2ef5b06..f0f5309a2d72 100644
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -48,7 +48,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
         __skb_push(skb, skb->mac_len);
 
         /* Segment inner packet. */
-        mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
+        mpls_features = skb->dev->mpls_features & features;
         segs = skb_mac_gso_segment(skb, mpls_features);
 
 
diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c
index a82077d9f59b..7c60ccd61a3e 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -665,7 +665,7 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
          * returned by nf_queue.  For instance, callers rely on -ECANCELED to
          * mean 'ignore this hook'.
          */
-        if (IS_ERR(segs))
+        if (IS_ERR_OR_NULL(segs))
                 goto out_err;
         queued = 0;
         err = 0;
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 2e31d9e7f4dc..e6d7255183eb 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -324,6 +324,8 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
         segs = __skb_gso_segment(skb, NETIF_F_SG, false);
         if (IS_ERR(segs))
                 return PTR_ERR(segs);
+        if (segs == NULL)
+                return -EINVAL;
 
         /* Queue all of the segments. */
         skb = segs;
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 499d6c18a8ce..7c532856b398 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -157,6 +157,8 @@ static int xfrm_output_gso(struct sk_buff *skb)
         kfree_skb(skb);
         if (IS_ERR(segs))
                 return PTR_ERR(segs);
+        if (segs == NULL)
+                return -EINVAL;
 
         do {
                 struct sk_buff *nskb = segs->next;