Comment 1 for bug 904617

Commit f462141f18ffdd75847f6459ef83d90b831d12c0 introduced clean up code
when usb_qdev_init() fails. Unfortunately it calls .handle_destroy()
when .init() was never invoked or failed. This can lead to crashes when
.handle_destroy() tries to clean up things that were never initialized.

This patch is careful to undo only those steps that completed along the
usb_qdev_init() code path. It's not as pretty as the unified error
handling in f462141f18ffdd75847f6459ef83d90b831d12c0 but it's necessary.

Signed-off-by: Stefan Hajnoczi <email address hidden>
---
 hw/usb-bus.c | 12 +++++-------
 1 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index 8cafb76..8203390 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -77,23 +77,21 @@ static int usb_qdev_init(DeviceState *qdev, DeviceInfo *base)
     QLIST_INIT(&dev->strings);
     rc = usb_claim_port(dev);
     if (rc != 0) {
- goto err;
+ return rc;
     }
     rc = dev->info->init(dev);
     if (rc != 0) {
- goto err;
+ usb_release_port(dev);
+ return rc;
     }
     if (dev->auto_attach) {
         rc = usb_device_attach(dev);
         if (rc != 0) {
- goto err;
+ usb_qdev_exit(qdev);
+ return rc;
         }
     }
     return 0;
-
-err:
- usb_qdev_exit(qdev);
- return rc;
 }

 static int usb_qdev_exit(DeviceState *qdev)
--
1.7.7.3