[PATCH] cdrom: gdrom: fix gendisk reference leak

[Guangshuo Li]

probe_gdrom() allocates a gendisk with blk_mq_alloc_disk(), but
remove_gdrom() only calls del_gendisk() during driver removal.

del_gendisk() unregisters the disk but does not drop the driver's
reference to the gendisk. Without a matching put_disk(), the reference
remains held and the gendisk is leaked.

Call put_disk() during remove_gdrom() to release the reference acquired
during disk allocation.

This issue was found by manual code inspection.

Fixes: 74ee1a7590b78 ("cdrom: Add support for Sega Dreamcast GD-ROM.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/cdrom/gdrom.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index 4ba4dd06cbf4..cd8c79e4a5ac 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -841,6 +841,7 @@ static void remove_gdrom(struct platform_device *devptr)
 	if (gdrom_major)
 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 	unregister_cdrom(gd.cd_info);
+	put_disk(gd.disk);
 	kfree(gd.cd_info);
 	kfree(gd.toc);
 }
-- 
2.43.0