target/linux/bcm27xx/patches-5.10/950-0735-xhci-guard-accesses-to-ep_state-in-xhci_endpoint_res.patch

   1 From 9d51ba9909129465493d56a7134ce4220d2e69e9 Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.com>
   3 Date: Mon, 16 Aug 2021 14:43:06 +0100
   4 Subject: [PATCH] xhci: guard accesses to ep_state in
   5  xhci_endpoint_reset()
   6
   7 See https://github.com/raspberrypi/linux/issues/3981
   8
   9 Two read-modify-write cycles on ep->ep_state are not guarded by
  10 xhci->lock. Fix these.
  11
  12 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
  13 ---
  14  drivers/usb/host/xhci.c | 5 +++++
  15  1 file changed, 5 insertions(+)
  16
  17 --- a/drivers/usb/host/xhci.c
  18 +++ b/drivers/usb/host/xhci.c
  19 @@ -3270,10 +3270,13 @@ static void xhci_endpoint_reset(struct u
  20                 return;
  21
  22         /* Bail out if toggle is already being cleared by a endpoint reset */
  23 +       spin_lock_irqsave(&xhci->lock, flags);
  24         if (ep->ep_state & EP_HARD_CLEAR_TOGGLE) {
  25                 ep->ep_state &= ~EP_HARD_CLEAR_TOGGLE;
  26 +               spin_unlock_irqrestore(&xhci->lock, flags);
  27                 return;
  28         }
  29 +       spin_unlock_irqrestore(&xhci->lock, flags);
  30         /* Only interrupt and bulk ep's use data toggle, USB2 spec 5.5.4-> */
  31         if (usb_endpoint_xfer_control(&host_ep->desc) ||
  32             usb_endpoint_xfer_isoc(&host_ep->desc))
  33 @@ -3359,8 +3362,10 @@ static void xhci_endpoint_reset(struct u
  34         xhci_free_command(xhci, cfg_cmd);
  35  cleanup:
  36         xhci_free_command(xhci, stop_cmd);
  37 +       spin_lock_irqsave(&xhci->lock, flags);
  38         if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
  39                 ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
  40 +       spin_unlock_irqrestore(&xhci->lock, flags);
  41  }
  42
  43  static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,