This is a note to let you know that I've just added the patch titled RDMA/rxe: Fix coding error 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-coding-error-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 10283284067658287c0e6e44962ff3415a5778c0 Author: Bob Pearson <rpearsonhpe@xxxxxxxxx> Date: Thu Jan 28 11:47:53 2021 -0600 RDMA/rxe: Fix coding error in rxe_rcv_mcast_pkt [ Upstream commit 8fc1b7027fc162738d5a85c82410e501a371a404 ] rxe_rcv_mcast_pkt() in rxe_recv.c can leak SKBs in error path code. The loop over the QPs attached to a multicast group creates new cloned SKBs for all but the last QP in the list and passes the SKB and its clones to rxe_rcv_pkt() for further processing. Any QPs that do not pass some checks are skipped. If the last QP in the list fails the tests the SKB is leaked. This patch checks if the SKB for the last QP was used and if not frees it. Also removes a redundant loop invariant assignment. Fixes: 8700e3e7c485 ("Soft RoCE driver") Fixes: 71abf20b28ff ("RDMA/rxe: Handle skb_clone() failure in rxe_recv.c") Link: https://lore.kernel.org/r/20210128174752.16128-1-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 2dc808988d949..369ba76f1605e 100644 --- a/drivers/infiniband/sw/rxe/rxe_recv.c +++ b/drivers/infiniband/sw/rxe/rxe_recv.c @@ -305,7 +305,6 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) list_for_each_entry(mce, &mcg->qp_list, qp_list) { qp = mce->qp; - pkt = SKB_TO_PKT(skb); /* validate qp for incoming packet */ err = check_type_state(rxe, pkt, qp); @@ -317,12 +316,18 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) continue; /* for all but the last qp create a new clone of the - * skb and pass to the qp. + * skb and pass to the qp. If an error occurs in the + * checks for the last qp in the list we need to + * free the skb since it hasn't been passed on to + * rxe_rcv_pkt() which would free it later. */ - if (mce->qp_list.next != &mcg->qp_list) + if (mce->qp_list.next != &mcg->qp_list) { per_qp_skb = skb_clone(skb, GFP_ATOMIC); - else + } else { per_qp_skb = skb; + /* show we have consumed the skb */ + skb = NULL; + } if (unlikely(!per_qp_skb)) continue; @@ -337,9 +342,8 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) rxe_drop_ref(mcg); /* drop ref from rxe_pool_get_key. */ - return; - err1: + /* free skb if not consumed */ kfree_skb(skb); }