rust: block: fix GenDiskBuilder failure cleanup

index 912cb805caf5..100c7b937a7e 100644
@@ -149,6 +149,17 @@ pub fn build<T: Operations>(
 
         // SAFETY: `gendisk` is a valid pointer as we initialized it above
         unsafe { (*gendisk).fops = &TABLE };
+        let cleanup_failure = ScopeGuard::new_with_data((gendisk, data), |(gendisk, data)| {
+            // SAFETY: `gendisk` came from `__blk_mq_alloc_disk()` above and
+            // has not been added to the VFS on this cleanup path.
+            unsafe { bindings::put_disk(gendisk) };
+            // SAFETY: `data` came from `into_foreign()` above and has not been
+            // converted back on this cleanup path.
+            drop(unsafe { T::QueueData::from_foreign(data) });
+        });
+        // The failure guard now owns both pieces of cleanup; the early guard
+        // must not run on this path anymore.
+        recover_data.dismiss();
 
         let mut writer = NullTerminatedFormatter::new(
             // SAFETY: `gendisk` points to a valid and initialized instance. We

@@ -172,7 +183,7 @@ pub fn build<T: Operations>(
             },
         )?;
 
-        recover_data.dismiss();
+        cleanup_failure.dismiss();
 
         // INVARIANT: `gendisk` was initialized above.
         // INVARIANT: `gendisk` was added to the VFS via `device_add_disk` above.