target/linux/bcm27xx/patches-5.4/950-0977-USB-gadget-f_hid-avoid-crashes-and-log-spam.patch

   1 From 22198e801db7542c59098a75bdab120bcbc42652 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Wed, 30 Sep 2020 19:23:43 +0100
   4 Subject: [PATCH] USB: gadget: f_hid: avoid crashes and log spam
   5
   6 Disconnecting and reconnecting the USB cable can lead to crashes and a
   7 variety of kernel log spam. Try to fix or minimise both.
   8
   9 See: https://github.com/raspberrypi/linux/issues/3870
  10
  11 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  12 ---
  13  drivers/usb/gadget/function/f_hid.c | 18 +++++++++++++++++-
  14  1 file changed, 17 insertions(+), 1 deletion(-)
  15
  16 --- a/drivers/usb/gadget/function/f_hid.c
  17 +++ b/drivers/usb/gadget/function/f_hid.c
  18 @@ -344,6 +344,11 @@ static ssize_t f_hidg_write(struct file
  19
  20         spin_lock_irqsave(&hidg->write_spinlock, flags);
  21
  22 +       if (!hidg->req) {
  23 +               spin_unlock_irqrestore(&hidg->write_spinlock, flags);
  24 +               return -ESHUTDOWN;
  25 +       }
  26 +
  27  #define WRITE_COND (!hidg->write_pending)
  28  try_again:
  29         /* write queue */
  30 @@ -364,7 +369,13 @@ try_again:
  31         count  = min_t(unsigned, count, hidg->report_length);
  32
  33         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
  34 -       status = copy_from_user(req->buf, buffer, count);
  35 +       if (req) {
  36 +               status = copy_from_user(req->buf, buffer, count);
  37 +       } else {
  38 +               ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
  39 +               status = -ESHUTDOWN;
  40 +               goto release_write_pending;
  41 +       }
  42
  43         if (status != 0) {
  44                 ERROR(hidg->func.config->cdev,
  45 @@ -393,6 +404,11 @@ try_again:
  46
  47         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
  48
  49 +       if (!hidg->in_ep->enabled) {
  50 +               ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
  51 +               status = -ESHUTDOWN;
  52 +               goto release_write_pending;
  53 +       }
  54         status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
  55         if (status < 0) {
  56                 ERROR(hidg->func.config->cdev,