[PATCH 3.5 73/78] usb: fix cleanup after failure in hub_configure()

[Luis Henriques]

3.5.7.26 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Krzysztof Mazur <krzysiek at podlesie.net>

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 at podlesie.net>
Acked-by: Alan Stern <stern at rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/core/hub.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b5503b0..b79aa83 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1562,6 +1562,7 @@ 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 */
-- 
1.8.3.2