[PATCH AUTOSEL 4.19 016/209] IB/hfi1: Error path MAD response size is incorrect

[Sasha Levin]

From: "Michael J. Ruhl" <michael.j.ruhl@xxxxxxxxx>

[ Upstream commit 935c84ac649a147e1aad2c48ee5c5a1a9176b2d0 ]

If a MAD packet has incorrect header information, the logic uses the reply
path to report the error.  The reply path expects *resp_len to be set
prior to return.  Unfortunately, *resp_len is set to 0 for this path.
This causes an incorrect response packet.

Fix by ensuring that the *resp_len is defaulted to the incoming packet
size (wc->bytes_len - sizeof(GRH)).

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/hw/hfi1/mad.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c
index f208a25d0e4f5..1669548e91dcf 100644
--- a/drivers/infiniband/hw/hfi1/mad.c
+++ b/drivers/infiniband/hw/hfi1/mad.c
@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2015-2017 Intel Corporation.
+ * Copyright(c) 2015-2018 Intel Corporation.
  *
  * This file is provided under a dual BSD/GPLv2 license.  When using or
  * redistributing this file, you may do so under either license.
@@ -4829,7 +4829,7 @@ static int hfi1_process_opa_mad(struct ib_device *ibdev, int mad_flags,
 	int ret;
 	int pkey_idx;
 	int local_mad = 0;
-	u32 resp_len = 0;
+	u32 resp_len = in_wc->byte_len - sizeof(*in_grh);
 	struct hfi1_ibport *ibp = to_iport(ibdev, port);
 
 	pkey_idx = hfi1_lookup_pkey_idx(ibp, LIM_MGMT_P_KEY);
-- 
2.20.1