[PATCH 1/5] spi: fix use-after-free on controller registration failure

[Johan Hovold]

Make sure to deregister from driver core also in the unlikely event that
per-cpu statistics allocation fails during controller registration to
avoid use-after-free (of driver resources) and unclocked register
accesses.

Fixes: 6598b91b5ac3 ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Cc: stable@xxxxxxxxxxxxxxx	# 6.0
Cc: David Jander <david@xxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
 drivers/spi/spi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 61f7bde8c7fb..9b2e307dc30a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3480,10 +3480,8 @@ int spi_register_controller(struct spi_controller *ctlr)
 		dev_info(dev, "controller is unqueued, this is deprecated\n");
 	} else if (ctlr->transfer_one || ctlr->transfer_one_message) {
 		status = spi_controller_initialize_queue(ctlr);
-		if (status) {
-			device_del(&ctlr->dev);
-			goto free_bus_id;
-		}
+		if (status)
+			goto del_ctrl;
 	}
 	/* Add statistics */
 	ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
@@ -3506,6 +3504,8 @@ int spi_register_controller(struct spi_controller *ctlr)
 
 destroy_queue:
 	spi_destroy_queue(ctlr);
+del_ctrl:
+	device_del(&ctlr->dev);
 free_bus_id:
 	mutex_lock(&board_lock);
 	idr_remove(&spi_controller_idr, ctlr->bus_num);
-- 
2.52.0