Commit 33d9a2c7 authored Nov 17, 2018 by Eric Dumazet Committed by David S. Miller Nov 17, 2018

net-gro: reset skb->pkt_type in napi_reuse_skb()



eth_type_trans() assumes initial value for skb->pkt_type
is PACKET_HOST.

This is indeed the value right after a fresh skb allocation.

However, it is possible that GRO merged a packet with a different
value (like PACKET_OTHERHOST in case macvlan is used), so
we need to make sure napi->skb will have pkt_type set back to
PACKET_HOST.

Otherwise, valid packets might be dropped by the stack because
their pkt_type is not PACKET_HOST.

napi_reuse_skb() was added in commit 96e93eab ("gro: Add
internal interfaces for VLAN"), but this bug always has
been there.

Fixes: 96e93eab ("gro: Add internal interfaces for VLAN")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5396527f

net/core/dev.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -5655,6 +5655,10 @@ static void napi_reuse_skb(struct napi_struct napi, struct sk_buff skb)
		skb->vlan_tci = 0;
		skb->dev = napi->dev;
		skb->skb_iif = 0;

		/* eth_type_trans() assumes pkt_type is PACKET_HOST */
		skb->pkt_type = PACKET_HOST;

		skb->encapsulation = 0;
		skb_shinfo(skb)->gso_type = 0;
		skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));

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