Merge branch 'fragment-stack-oob-read'

Davide Caratti says:

====================
fix stack OOB read while fragmenting IPv4 packets

- patch 1/2 fixes openvswitch IPv4 fragmentation, that does a stack OOB
read after commit d52e5a7e ("ipv4: lock mtu in fnhe when received
PMTU < net.ipv4.route.min_pmt")
- patch 2/2 fixes the same issue in TC 'sch_frag' code
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/actions.c

@@ -827,17 +827,17 @@ static void ovs_fragment(struct net *net, struct vport *vport,
 	}
 
 	if (key->eth.type == htons(ETH_P_IP)) {
-		struct dst_entry ovs_dst;
+		struct rtable ovs_rt = { 0 };
 		unsigned long orig_dst;
 
 		prepare_frag(vport, skb, orig_network_offset,
 			     ovs_key_mac_proto(key));
-		dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
+		dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
-		ovs_dst.dev = vport->dev;
+		ovs_rt.dst.dev = vport->dev;
 
 		orig_dst = skb->_skb_refdst;
-		skb_dst_set_noref(skb, &ovs_dst);
+		skb_dst_set_noref(skb, &ovs_rt.dst);
 		IPCB(skb)->frag_max_size = mru;
 
 		ip_do_fragment(net, skb->sk, skb, ovs_vport_output);

net/sched/sch_frag.c

@@ -90,16 +90,16 @@ static int sch_fragment(struct net *net, struct sk_buff *skb,
 	}
 
 	if (skb_protocol(skb, true) == htons(ETH_P_IP)) {
-		struct dst_entry sch_frag_dst;
+		struct rtable sch_frag_rt = { 0 };
 		unsigned long orig_dst;
 
 		sch_frag_prepare_frag(skb, xmit);
-		dst_init(&sch_frag_dst, &sch_frag_dst_ops, NULL, 1,
+		dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, 1,
 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
-		sch_frag_dst.dev = skb->dev;
+		sch_frag_rt.dst.dev = skb->dev;
 
 		orig_dst = skb->_skb_refdst;
-		skb_dst_set_noref(skb, &sch_frag_dst);
+		skb_dst_set_noref(skb, &sch_frag_rt.dst);
 		IPCB(skb)->frag_max_size = mru;
 
 		ret = ip_do_fragment(net, skb->sk, skb, sch_frag_xmit);