RDMA/rxe: Fix missed IB reference counting in loopback

When the noted patch below extending the reference taken by rxe_get_dev_from_net() in rxe_udp_encap_recv() until each skb is freed it was not matched by a reference in the loopback path resulting in underflows. Fixes: 899aba8 ("RDMA/rxe: Fix FIXME in rxe_udp_encap_recv()") Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Bob Pearson <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>
LoveHeat · Mar 5, 2021 · 21e27ac · 21e27ac
1 parent cca7f12
commit 21e27ac
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -407,14 +407,22 @@ int rxe_send(struct rxe_pkt_info *pkt, struct sk_buff *skb)
 	return 0;
 }
 
+/* fix up a send packet to match the packets
+ * received from UDP before looping them back
+ */
 void rxe_loopback(struct sk_buff *skb)
 {
+	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+
 	if (skb->protocol == htons(ETH_P_IP))
 		skb_pull(skb, sizeof(struct iphdr));
 	else
 		skb_pull(skb, sizeof(struct ipv6hdr));
 
-	rxe_rcv(skb);
+	if (WARN_ON(!ib_device_try_get(&pkt->rxe->ib_dev)))
+		kfree_skb(skb);
+	else
+		rxe_rcv(skb);
 }
 
 struct sk_buff *rxe_init_packet(struct rxe_dev *rxe, struct rxe_av *av,