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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, Leon Romanovsky <leonro@mellanox.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.9 407/757] RDMA/ucma: Add missing locking around rdma_leave_multicast()
Date:   Tue, 27 Oct 2020 14:50:57 +0100
Message-Id: <20201027135509.666453539@linuxfoundation.org>
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From: Jason Gunthorpe <jgg@nvidia.com>

[ Upstream commit 38e03d092699891c3237b5aee9e8029d4ede0956 ]

All entry points to the rdma_cm from a ULP must be single threaded,
even this error unwinds. Add the missing locking.

Fixes: 7c11910783a1 ("RDMA/ucma: Put a lock around every call to the rdma_cm layer")
Link: https://lore.kernel.org/r/20200818120526.702120-11-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/ucma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 75ccc31cf0b15..6f42ff8f2ec57 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1512,7 +1512,9 @@ static ssize_t ucma_process_join(struct ucma_file *file,
 	return 0;
 
 err3:
+	mutex_lock(&ctx->mutex);
 	rdma_leave_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr);
+	mutex_unlock(&ctx->mutex);
 	ucma_cleanup_mc_events(mc);
 err2:
 	xa_erase(&multicast_table, mc->id);
-- 
2.25.1