[PATCH 6.1 247/473] RDMA/rxe: Fix incorrect rxe_put in error path

Greg Kroah-Hartman
2024-06-06T14:16:03Z

From: Bob Pearson <rpearsonhpe@gmail.com>

[ Upstream commit 8776618dbbd1b6f210b31509507e1aad461d6435 ]

In rxe_send() a ref is taken on the qp to keep it alive until the
kfree_skb() has a chance to call the skb destructor rxe_skb_tx_dtor()
which drops the reference. If the packet has an incorrect protocol the
error path just calls kfree_skb() which will call the destructor which
will drop the ref. Currently the driver also calls rxe_put() which is
incorrect. Additionally since the packets sent to rxe_send() are under the
control of the driver and it only ever produces IPV4 or IPV6 packets the
simplest fix is to remove all the code in this block.

Link: https://lore.kernel.org/r/20240329145513.35381-12-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Fixes: 9eb7f8e44d13 ("IB/rxe: Move refcounting earlier in rxe_send()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/rxe/rxe_net.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index 6bd6ed80f4a6c..779cd547ce839 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -366,18 +366,10 @@ static int rxe_send(struct sk_buff *skb, struct rxe_pkt_info *pkt)
rxe_get(pkt->qp);
atomic_inc(&pkt->qp->skb_out);

- if (skb->protocol == htons(ETH_P_IP)) {
+ if (skb->protocol == htons(ETH_P_IP))
err = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
- } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ else
err = ip6_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
- } else {
- rxe_dbg_qp(pkt->qp, "Unknown layer 3 protocol: %d\n",
- skb->protocol);
- atomic_dec(&pkt->qp->skb_out);
- rxe_put(pkt->qp);
- kfree_skb(skb);
- return -EINVAL;
- }

if (unlikely(net_xmit_eval(err))) {
rxe_dbg_qp(pkt->qp, "error sending packet: %d\n", err);
--
2.43.0