[PATCH AUTOSEL 4.4 03/16] RDMA/cm: Add missing locking around id.state in cm_dup_req_handler

[Sasha Levin <sashal@kernel.org>]

From: Jason Gunthorpe <jgg@mellanox.com>

[ Upstream commit d1de9a88074b66482443f0cd91618d7b51a7c9b6 ]

All accesses to id.state must be done under the spinlock.

Fixes: a977049dacde ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-10-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/cm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 53c622c99ee40..7bf98d72a4559 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -1544,8 +1544,12 @@ static void cm_dup_req_handler(struct cm_work *work,
 			counter[CM_REQ_COUNTER]);
 
 	/* Quick state check to discard duplicate REQs. */
-	if (cm_id_priv->id.state == IB_CM_REQ_RCVD)
+	spin_lock_irq(&cm_id_priv->lock);
+	if (cm_id_priv->id.state == IB_CM_REQ_RCVD) {
+		spin_unlock_irq(&cm_id_priv->lock);
 		return;
+	}
+	spin_unlock_irq(&cm_id_priv->lock);
 
 	ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
 	if (ret)
-- 
2.20.1