Xen-netback: Fix issue caused by using gso_type wrongly

[ Upstream commit 5bd076708664313f2bdbbc1cf71093313b7774a1 ]

Current netback uses gso_type to check whether the skb contains
gso offload, and this is wrong. Gso_size is the right one to
check gso existence, and gso_type is only used to check gso type.

Some skbs contains nonzero gso_type and zero gso_size, current
netback would treat these skbs as gso and create wrong response
for this. This also causes ssh failure to domu from other server.

V2: use skb_is_gso function as Paul Durrant suggested

Signed-off-by: Annie Li <annie.li@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 78425554a537579b01378b99295913c1706f0b0a..77c1c44b567d0a41e5034647296382ba33cec55f 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -338,7 +338,7 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
        struct gnttab_copy *copy_gop;
        struct xenvif_rx_meta *meta;
        unsigned long bytes;
-       int gso_type;
+       int gso_type = XEN_NETIF_GSO_TYPE_NONE;
 
        /* Data must not cross a page boundary. */
        BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
@@ -397,12 +397,12 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
                }
 
                /* Leave a gap for the GSO descriptor. */
-               if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
-                       gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
-               else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
-                       gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
-               else
-                       gso_type = XEN_NETIF_GSO_TYPE_NONE;
+               if (skb_is_gso(skb)) {
+                       if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+                               gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+                       else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+                               gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+               }
 
                if (*head && ((1 << gso_type) & vif->gso_mask))
                        vif->rx.req_cons++;
@@ -436,19 +436,15 @@ static int xenvif_gop_skb(struct sk_buff *skb,
        int head = 1;
        int old_meta_prod;
        int gso_type;
-       int gso_size;
 
        old_meta_prod = npo->meta_prod;
 
-       if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
-               gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
-               gso_size = skb_shinfo(skb)->gso_size;
-       } else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
-               gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
-               gso_size = skb_shinfo(skb)->gso_size;
-       } else {
-               gso_type = XEN_NETIF_GSO_TYPE_NONE;
-               gso_size = 0;
+       gso_type = XEN_NETIF_GSO_TYPE_NONE;
+       if (skb_is_gso(skb)) {
+               if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+                       gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+               else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+                       gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
        }
 
        /* Set up a GSO prefix descriptor, if necessary */
@@ -456,7 +452,7 @@ static int xenvif_gop_skb(struct sk_buff *skb,
                req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
                meta = npo->meta + npo->meta_prod++;
                meta->gso_type = gso_type;
-               meta->gso_size = gso_size;
+               meta->gso_size = skb_shinfo(skb)->gso_size;
                meta->size = 0;
                meta->id = req->id;
        }
@@ -466,7 +462,7 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 
        if ((1 << gso_type) & vif->gso_mask) {
                meta->gso_type = gso_type;
-               meta->gso_size = gso_size;
+               meta->gso_size = skb_shinfo(skb)->gso_size;
        } else {
                meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
                meta->gso_size = 0;