net: preserve IP control block during GSO segmentation
Skb_gso_segment() uses skb control block during segmentation.
This patch adds 32-bytes room for previous control block which
will be copied into all resulting segments.
This patch fixes kernel crash during fragmenting forwarded packets.
Fragmentation requires valid IP CB in skb for clearing ip options.
Also patch removes custom save/restore in ovs code, now it's redundant.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 91a8b00..deadfda 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -336,12 +336,10 @@
unsigned short gso_type = skb_shinfo(skb)->gso_type;
struct sw_flow_key later_key;
struct sk_buff *segs, *nskb;
- struct ovs_skb_cb ovs_cb;
int err;
- ovs_cb = *OVS_CB(skb);
+ BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_SGO_CB_OFFSET);
segs = __skb_gso_segment(skb, NETIF_F_SG, false);
- *OVS_CB(skb) = ovs_cb;
if (IS_ERR(segs))
return PTR_ERR(segs);
if (segs == NULL)
@@ -359,7 +357,6 @@
/* Queue all of the segments. */
skb = segs;
do {
- *OVS_CB(skb) = ovs_cb;
if (gso_type & SKB_GSO_UDP && skb != segs)
key = &later_key;