Check the return value of dma_async_device_register() in the probe
path and propagate errors instead of silently returning success.
Previously, a registration failure would cause a NULL pointer
dereference in list_del_rcu() during remove when
dma_async_device_unregister() tried to remove the device's
global_node from a list it was never added to.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <redacted>
---
 drivers/dma/fsldma.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 0e2f84862261..89b88447be1b 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c

@@ -1293,7 +1293,11 @@ static int fsldma_of_probe(struct platform_device *op)
 		goto out_free_fdev;
 	}
 
-	dma_async_device_register(&fdev->common);
+	err = dma_async_device_register(&fdev->common);
+	if (err) {
+		dev_err(fdev->dev, "unable to register DMA device\n");
+		goto out_free_fdev;
+	}
 	return 0;
 
 out_free_fdev:

-- 
2.54.0