[PATCH 5.9 506/757] RDMA/rxe: Handle skb_clone() failure in rxe_recv.c

[Greg Kroah-Hartman]

From: Bob Pearson <rpearsonhpe@xxxxxxxxx>

[ Upstream commit 71abf20b28ff87fee6951ec2218d5ce7969c4e87 ]

If skb_clone() is unable to allocate memory for a new sk_buff this is not
detected by the current code.

Check for a NULL return and continue. This is similar to other errors in
this loop over QPs attached to the multicast address and consistent with
the unreliable UD transport.

Fixes: e7ec96fc7932f ("RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt()")
Addresses-Coverity-ID: 1497804: Null pointer dereferences (NULL_RETURNS)
Link: https://lore.kernel.org/r/20201013184236.5231-1-rpearson@xxxxxxx
Signed-off-by: Bob Pearson <rpearson@xxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_recv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
index 967ee8e1699cd..2da4187db80c9 100644
--- a/drivers/infiniband/sw/rxe/rxe_recv.c
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -298,6 +298,9 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb)
 		else
 			per_qp_skb = skb;
 
+		if (unlikely(!per_qp_skb))
+			continue;
+
 		per_qp_pkt = SKB_TO_PKT(per_qp_skb);
 		per_qp_pkt->qp = qp;
 		rxe_add_ref(qp);
-- 
2.25.1