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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        =?UTF-8?q?H=C3=A5kon=20Bugge?= <haakon.bugge@oracle.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 486/677] RDMA/core: Fix corrupted SL on passive side
Date:   Wed, 12 May 2021 16:48:52 +0200
Message-Id: <20210512144853.525636321@linuxfoundation.org>
In-Reply-To: <20210512144837.204217980@linuxfoundation.org>
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From: Håkon Bugge <haakon.bugge@oracle.com>

[ Upstream commit 194f64a3cad3ab9e381e996a13089de3215d1887 ]

On RoCE systems, a CM REQ contains a Primary Hop Limit > 1 and Primary
Subnet Local is zero.

In cm_req_handler(), the cm_process_routed_req() function is called. Since
the Primary Subnet Local value is zero in the request, and since this is
RoCE (Primary Local LID is permissive), the following statement will be
executed:

      IBA_SET(CM_REQ_PRIMARY_SL, req_msg, wc->sl);

This corrupts SL in req_msg if it was different from zero. In other words,
a request to setup a connection using an SL != zero, will not be honored,
and a connection using SL zero will be created instead.

Fixed by not calling cm_process_routed_req() on RoCE systems, the
cm_process_route_req() is only for IB anyhow.

Fixes: 3971c9f6dbf2 ("IB/cm: Add interim support for routed paths")
Link: https://lore.kernel.org/r/1616420132-31005-1-git-send-email-haakon.bugge@oracle.com
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/cm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 3d194bb60840..6adbaea358ae 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -2138,7 +2138,8 @@ static int cm_req_handler(struct cm_work *work)
 		goto destroy;
 	}
 
-	cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
+	if (cm_id_priv->av.ah_attr.type != RDMA_AH_ATTR_TYPE_ROCE)
+		cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
 
 	memset(&work->path[0], 0, sizeof(work->path[0]));
 	if (cm_req_has_alt_path(req_msg))
-- 
2.30.2