From 167657a1bb5fcde53ac304ce6c564bd90a2f9185 Mon Sep 17 00:00:00 2001

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Date: Fri, 18 Sep 2020 16:17:51 +0300

Subject: [PATCH] xhci: don't create endpoint debugfs entry before ring buffer

 is set.

Git-commit: 167657a1bb5fcde53ac304ce6c564bd90a2f9185

References: git-fixes

Patch-mainline: v5.10-rc1

Make sure xHC completes the configure endpoint command and xhci driver

sets the ring pointers correctly before we create the user readable

debugfs file.

In theory there was a small gap where a user could have read the

debugfs file and cause a NULL pointer dereference error as ring

pointer was not yet set, in practise we want this change to simplify

the upcoming streams debugfs support.

Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver")

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>

Link: https://lore.kernel.org/r/20200918131752.16488-10-mathias.nyman@linux.intel.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Oliver Neukum <oneukum@suse.com>

---

 drivers/usb/host/xhci.c |    3 +--

 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/usb/host/xhci.c

+++ b/drivers/usb/host/xhci.c

@@ -1899,8 +1899,6 @@ static int xhci_add_endpoint(struct usb_

 	/* Store the usb_device pointer for later use */

 	ep->hcpriv = udev;

-	xhci_debugfs_create_endpoint(xhci, virt_dev, ep_index);

-

 	xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",

 			(unsigned int) ep->desc.bEndpointAddress,

 			udev->slot_id,

@@ -2927,6 +2925,7 @@ static int xhci_check_bandwidth(struct u

 		xhci_check_bw_drop_ep_streams(xhci, virt_dev, i);

 		virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;

 		virt_dev->eps[i].new_ring = NULL;

+		xhci_debugfs_create_endpoint(xhci, virt_dev, i);

 	}

 command_cleanup:

 	kfree(command->completion);