usb: fix cleanup after failure in hub_configure()

commit d0308d4b6b02597f39fc31a9bddf7bb3faad5622 upstream.

If the hub_configure() fails after setting the hdev->maxchild
the hub->ports might be NULL or point to uninitialized kzallocated
memory causing NULL pointer dereference in hub_quiesce() during cleanup.

Now after such error the hdev->maxchild is set to 0 to avoid cleanup
of uninitialized ports.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 6cf2ae0aa1f7..a7515d165390 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1568,6 +1568,7 @@ static int hub_configure(struct usb_hub *hub,
         return 0;
 
 fail:
+        hdev->maxchild = 0;
         dev_err (hub_dev, "config failed, %s (err %d)\n",
                         message, ret);
         /* hub_disconnect() frees urb and descriptor */