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 96e93ea ("gro: Add internal interfaces for VLAN"), but this bug always has been there. Fixes: 96e93ea ("gro: Add internal interfaces for VLAN") Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
randomhydrosol · Nov 18, 2018 · 33d9a2c · 33d9a2c
1 parent 5396527
commit 33d9a2c
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/net/core/dev.c b/net/core/dev.c
@@ -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));