diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 64bb38c95895..6627a381f65a 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1373,6 +1373,13 @@ static CLOSURE_CALLBACK(cached_dev_free)
 
 	mutex_unlock(&bch_register_lock);
 
+	/*
+	 * Wait for any pending sb_write to complete before free.
+	 * The sb_bio is embedded in struct cached_dev, so we must
+	 * ensure no I/O is in progress.
+	 */
+	closure_sync(&dc->sb_write);
+
 	if (dc->sb_disk)
 		folio_put(virt_to_folio(dc->sb_disk));