[PATCH] floppy: unregister platform device on add_disk failure

[Guangshuo Li <lgs201920130244@gmail.com>]

The change referenced by the Fixes tag reverted a previous fix because
that fix added incorrect cleanup for the platform_device_register()
failure path.

However, reverting the whole change also removed the cleanup for a later
failure path. If platform_device_register() succeeds but device_add_disk()
fails, the current floppy platform device has already been registered and
registered[drive] has been set.

The common out_remove_drives path uses while (drive--), so it starts from
the previous drive and does not unregister the current one. As a result,
the platform device registered for the failing drive is leaked.

Unregister the current platform device directly on the device_add_disk()
failure path, where platform_device_register() is known to have
succeeded. Leave the platform_device_register() failure path unchanged.

Fixes: 895a9b37917d ("Revert "floppy: fix reference leak on platform_device_register() failure"")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/block/floppy.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index f04397b8e381..7a34af534460 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4729,8 +4729,11 @@ static int __init do_floppy_init(void)
 
 		err = device_add_disk(&floppy_device[drive].dev,
 				      disks[drive][0], NULL);
-		if (err)
+		if (err) {
+			platform_device_unregister(&floppy_device[drive]);
+			registered[drive] = false;
 			goto out_remove_drives;
+		}
 	}
 
 	return 0;
-- 
2.43.0