[PATCH 4.9 30/96] xhci: Fix ring leak in failure path of xhci_alloc_virt_device()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Ben Hutchings <ben.hutchings@codethink.co.uk>

This is a stable-only fix for the backport of commit 5d9b70f7d52e
("xhci: Don't add a virt_dev to the devs array before it's fully
allocated").

In branches that predate commit c5628a2af83a ("xhci: remove endpoint
ring cache") there is an additional failure path in
xhci_alloc_virt_device() where ring cache allocation fails, in
which case we need to free the ring allocated for endpoint 0.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Mathias Nyman <mathias.nyman@intel.com>
---
This is build-tested only.

Ben.

 drivers/usb/host/xhci-mem.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1086,7 +1086,8 @@ int xhci_alloc_virt_device(struct xhci_h
 
 	return 1;
 fail:
-
+	if (dev->eps[0].ring)
+		xhci_ring_free(xhci, dev->eps[0].ring);
 	if (dev->in_ctx)
 		xhci_free_container_ctx(xhci, dev->in_ctx);
 	if (dev->out_ctx)