This is a note to let you know that I've just added the patch titled RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-rxe-fix-skb-lifetime-in-rxe_rcv_mcast_pkt.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a5fa90b8b6f42f2f689e2a0e0015e5920ef11a98 Author: Bob Pearson <rpearsonhpe@xxxxxxxxx> Date: Thu Oct 8 15:36:52 2020 -0500 RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt() [ Upstream commit e7ec96fc7932f48a6d6cdd05bf82004a1a04285b ] The changes referenced below replaced sbk_clone)_ by taking additional references, passing the skb along and then freeing the skb. This deleted the packets before they could be processed and additionally passed bad data in each packet. Since pkt is stored in skb->cb changing pkt->qp changed it for all the packets. Replace skb_get() by sbk_clone() in rxe_rcv_mcast_pkt() for cases where multiple QPs are receiving multicast packets on the same address. Delete kfree_skb() because the packets need to live until they have been processed by each QP. They are freed later. Fixes: 86af61764151 ("IB/rxe: remove unnecessary skb_clone") Fixes: fe896ceb5772 ("IB/rxe: replace refcount_inc with skb_get") Link: https://lore.kernel.org/r/20201008203651.256958-1-rpearson@xxxxxxx Signed-off-by: Bob Pearson <rpearson@xxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c index 46e111c218fd4..be6416a982c70 100644 --- a/drivers/infiniband/sw/rxe/rxe_recv.c +++ b/drivers/infiniband/sw/rxe/rxe_recv.c @@ -281,6 +281,8 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) struct rxe_mc_elem *mce; struct rxe_qp *qp; union ib_gid dgid; + struct sk_buff *per_qp_skb; + struct rxe_pkt_info *per_qp_pkt; int err; if (skb->protocol == htons(ETH_P_IP)) @@ -309,21 +311,26 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) if (err) continue; - /* if *not* the last qp in the list - * increase the users of the skb then post to the next qp + /* for all but the last qp create a new clone of the + * skb and pass to the qp. */ if (mce->qp_list.next != &mcg->qp_list) - skb_get(skb); + per_qp_skb = skb_clone(skb, GFP_ATOMIC); + else + per_qp_skb = skb; - pkt->qp = qp; + per_qp_pkt = SKB_TO_PKT(per_qp_skb); + per_qp_pkt->qp = qp; rxe_add_ref(qp); - rxe_rcv_pkt(pkt, skb); + rxe_rcv_pkt(per_qp_pkt, per_qp_skb); } spin_unlock_bh(&mcg->mcg_lock); rxe_drop_ref(mcg); /* drop ref from rxe_pool_get_key. */ + return; + err1: kfree_skb(skb); }