[PATCH 4.20 63/80] IB/hfi1: Add limit test for RC/UC send via loopback

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>

commit 09ce351dff8e7636af0beb72cd4a86c3904a0500 upstream.

Fix potential memory corruption and panic in loopback for IB_WR_SEND
variants.

The code blindly assumes the posted length will fit in the fetched rwqe,
which is not a valid assumption.

Fix by adding a limit test, and triggering the appropriate send completion
and putting the QP in an error state.  This mimics the handling for
non-loopback QPs.

Fixes: 15703461533a ("IB/{hfi1, qib, rdmavt}: Move ruc_loopback to rdmavt")
Cc: <stable@xxxxxxxxxxxxxxx> #v4.20+
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/sw/rdmavt/qp.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -2903,6 +2903,8 @@ send:
 			goto op_err;
 		if (!ret)
 			goto rnr_nak;
+		if (wqe->length > qp->r_len)
+			goto inv_err;
 		break;
 
 	case IB_WR_RDMA_WRITE_WITH_IMM:
@@ -3071,7 +3073,10 @@ op_err:
 	goto err;
 
 inv_err:
-	send_status = IB_WC_REM_INV_REQ_ERR;
+	send_status =
+		sqp->ibqp.qp_type == IB_QPT_RC ?
+			IB_WC_REM_INV_REQ_ERR :
+			IB_WC_SUCCESS;
 	wc.status = IB_WC_LOC_QP_OP_ERR;
 	goto err;