releases/5.4.118/xhci-check-control-context-is-valid-before-dereferen.patch

   1 From d43fa5edb5a05c6f8278fc7e4c4dd6f1f4d3bf64 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Tue, 6 Apr 2021 10:02:06 +0300
   4 Subject: xhci: check control context is valid before dereferencing it.
   5
   6 From: Mathias Nyman <mathias.nyman@linux.intel.com>
   7
   8 [ Upstream commit 597899d2f7c5619c87185ee7953d004bd37fd0eb ]
   9
  10 Don't dereference ctrl_ctx before checking it's valid.
  11 Issue reported by Klockwork
  12
  13 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
  14 Link: https://lore.kernel.org/r/20210406070208.3406266-3-mathias.nyman@linux.intel.com
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  16 Signed-off-by: Sasha Levin <sashal@kernel.org>
  17 ---
  18  drivers/usb/host/xhci.c | 8 ++++++++
  19  1 file changed, 8 insertions(+)
  20
  21 diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
  22 index b5080bc1689e..143e4002e561 100644
  23 --- a/drivers/usb/host/xhci.c
  24 +++ b/drivers/usb/host/xhci.c
  25 @@ -3227,6 +3227,14 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
  26
  27         /* config ep command clears toggle if add and drop ep flags are set */
  28         ctrl_ctx = xhci_get_input_control_ctx(cfg_cmd->in_ctx);
  29 +       if (!ctrl_ctx) {
  30 +               spin_unlock_irqrestore(&xhci->lock, flags);
  31 +               xhci_free_command(xhci, cfg_cmd);
  32 +               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
  33 +                               __func__);
  34 +               goto cleanup;
  35 +       }
  36 +
  37         xhci_setup_input_ctx_for_config_ep(xhci, cfg_cmd->in_ctx, vdev->out_ctx,
  38                                            ctrl_ctx, ep_flag, ep_flag);
  39         xhci_endpoint_copy(xhci, cfg_cmd->in_ctx, vdev->out_ctx, ep_index);
  40 --
  41 2.30.2
  42