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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Anirudh Rayabharam <mail@anirudhrb.com>,
        Alexandre Bounine <alex.bou9@gmail.com>,
        Matt Porter <mporter@kernel.crashing.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        stable <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 45/69] rapidio: handle create_workqueue() failure
Date:   Mon,  3 May 2021 13:57:12 +0200
Message-Id: <20210503115736.2104747-46-gregkh@linuxfoundation.org>
In-Reply-To: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
References: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
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From: Anirudh Rayabharam <mail@anirudhrb.com>

In case create_workqueue() fails, release all resources and return -ENOMEM
to caller to avoid potential NULL pointer deref later. Move up the
create_workequeue() call to return early and avoid unwinding the call to
riocm_rx_fill().

Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/rapidio/rio_cm.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index e6c16f04f2b4..db4c265287ae 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -2127,6 +2127,14 @@ static int riocm_add_mport(struct device *dev,
 		return -ENODEV;
 	}
 
+	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
+	if (!cm->rx_wq) {
+		rio_release_inb_mbox(mport, cmbox);
+		rio_release_outb_mbox(mport, cmbox);
+		kfree(cm);
+		return -ENOMEM;
+	}
+
 	/*
 	 * Allocate and register inbound messaging buffers to be ready
 	 * to receive channel and system management requests
@@ -2137,7 +2145,6 @@ static int riocm_add_mport(struct device *dev,
 	cm->rx_slots = RIOCM_RX_RING_SIZE;
 	mutex_init(&cm->rx_lock);
 	riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
-	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
 	INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
 
 	cm->tx_slot = 0;
-- 
2.31.1