[PATCH] usb: xhci: disable the correct slot on alloc_dev failure

[raoxu]

From: Xu Rao <raoxu@xxxxxxxxxxxxx>

xhci_alloc_dev() stores the Slot ID returned by the Enable Slot command
in the local slot_id variable.  udev->slot_id is updated only after
xhci_alloc_virt_device() succeeds.

If endpoint resource reservation or virtual device allocation fails
before that update, the error path passes udev->slot_id to
xhci_disable_and_free_slot().  During initial enumeration this is slot 0.
When reallocating a device whose virtual device is missing or belongs to
another usb_device, udev->slot_id may contain a stale Slot ID.
The newly enabled slot can therefore remain active, or the wrong slot can
be disabled.

Pass slot_id, which identifies the slot enabled by this invocation.
xhci_disable_and_free_slot() already handles a missing xhci->devs entry.

Fixes: 3ffbba9511b4 ("USB: xhci: Allocate and address USB devices")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Xu Rao <raoxu@xxxxxxxxxxxxx>
---
 drivers/usb/host/xhci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 091c82ca8ee2..dd8c12380e0c 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4298,7 +4298,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
 	return 1;

 disable_slot:
-	xhci_disable_and_free_slot(xhci, udev->slot_id);
+	xhci_disable_and_free_slot(xhci, slot_id);

 	return 0;
 }
--
2.50.1