net: preserve IP control block during GSO segmentation
[ Upstream commit 9207f9d45b0ad071baa128e846d7e7ed85016df3 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 27e1496..b3fe02a 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -337,12 +337,10 @@
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)
@@ -360,7 +358,6 @@
/* Queue all of the segments. */
skb = segs;
do {
- *OVS_CB(skb) = ovs_cb;
if (gso_type & SKB_GSO_UDP && skb != segs)
key = &later_key;