From: Bob Pearson <rpearsonhpe@xxxxxxxxx> [ Upstream commit 9a3763e87379c97a78b7c6c6f40720b1e877174f ] In rxe_net.c a received packet, from udp or loopback, is passed to rxe_rcv() in rxe_recv.c as a udp packet. I.e. skb->data is pointing at the udp header. But rxe_rcv() makes length checks to verify the packet is long enough to hold the roce headers as if it were a roce packet. I.e. skb->data pointing at the bth header. A runt packet would appear to have 8 more bytes than it actually does which may lead to incorrect behavior. This patch calls skb_pull() to adjust the skb to point at the bth header before calling rxe_rcv() which fixes this error. Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20230517172242.1806340-1-rpearsonhpe@xxxxxxxxx Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/infiniband/sw/rxe/rxe_net.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c index 35f327b9d4b8e..65d16024b3bf6 100644 --- a/drivers/infiniband/sw/rxe/rxe_net.c +++ b/drivers/infiniband/sw/rxe/rxe_net.c @@ -156,6 +156,9 @@ static int rxe_udp_encap_recv(struct sock *sk, struct sk_buff *skb) pkt->mask = RXE_GRH_MASK; pkt->paylen = be16_to_cpu(udph->len) - sizeof(*udph); + /* remove udp header */ + skb_pull(skb, sizeof(struct udphdr)); + rxe_rcv(skb); return 0; @@ -397,6 +400,9 @@ static int rxe_loopback(struct sk_buff *skb, struct rxe_pkt_info *pkt) return -EIO; } + /* remove udp header */ + skb_pull(skb, sizeof(struct udphdr)); + rxe_rcv(skb); return 0; -- 2.39.2