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 <eduma...@google.com>
---
net/core/dev.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/core/dev.c b/net/core/dev.c
index
0ffcbdd55fa9ee545c807f2ed3fc178830e3075a..689ff83af855660f8b9aaa0266b5e509cd0839cb
100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5655,6 +5655,11 @@ 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 */
+ WARN_ON_ONCE(skb->pkt_type != PACKET_HOST);
+ skb->pkt_type = PACKET_HOST;
+
skb->encapsulation = 0;
skb_shinfo(skb)->gso_type = 0;
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
--
2.19.1.1215.g8438c0b245-goog
