4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 33d9a2c72f086cbf1087b2fd2d1a15aa9df14a7f ]
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 96e93eab2033 ("gro: Add internal interfaces for VLAN"), but this bug always has been there.
Fixes: 96e93eab2033 ("gro: Add internal interfaces for VLAN") Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/dev.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/net/core/dev.c +++ b/net/core/dev.c @@ -4756,6 +4756,10 @@ static void napi_reuse_skb(struct napi_s 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));