target/linux/generic/patches-4.4/084-0002-usb-core-usbport-Use-proper-LED-API-to-fix-potential.patch

   1 From 89778ba335e302a450932ce5b703c1ee6216e949 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Tue, 6 Dec 2016 00:39:33 +0100
   4 Subject: [PATCH] usb: core: usbport: Use proper LED API to fix potential crash
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Calling brightness_set manually isn't safe as some LED drivers don't
  10 implement this callback. The best idea is to just use a proper helper
  11 which will fallback to the brightness_set_blocking callback if needed.
  12
  13 This fixes:
  14 [ 1461.761528] Unable to handle kernel NULL pointer dereference at virtual address 00000000
  15 (...)
  16 [ 1462.117049] Backtrace:
  17 [ 1462.119521] [<bf228164>] (usbport_trig_port_store [ledtrig_usbport]) from [<c023f758>] (dev_attr_store+0x20/0x2c)
  18 [ 1462.129826]  r7:dcabc7c0 r6:dee0ff80 r5:00000002 r4:bf228164
  19 [ 1462.135511] [<c023f738>] (dev_attr_store) from [<c0169310>] (sysfs_kf_write+0x48/0x4c)
  20 [ 1462.143459]  r5:00000002 r4:c023f738
  21 [ 1462.147049] [<c01692c8>] (sysfs_kf_write) from [<c0168ab8>] (kernfs_fop_write+0xf8/0x1f8)
  22 [ 1462.155258]  r5:00000002 r4:df4a1000
  23 [ 1462.158850] [<c01689c0>] (kernfs_fop_write) from [<c0100c78>] (__vfs_write+0x34/0x120)
  24 [ 1462.166800]  r10:00000000 r9:dee0e000 r8:c000fc24 r7:00000002 r6:dee0ff80 r5:c01689c0
  25 [ 1462.174660]  r4:df727a80
  26 [ 1462.177204] [<c0100c44>] (__vfs_write) from [<c0101ae4>] (vfs_write+0xac/0x170)
  27 [ 1462.184543]  r9:dee0e000 r8:c000fc24 r7:dee0ff80 r6:b6f092d0 r5:df727a80 r4:00000002
  28 [ 1462.192319] [<c0101a38>] (vfs_write) from [<c01028dc>] (SyS_write+0x4c/0xa8)
  29 [ 1462.199396]  r9:dee0e000 r8:c000fc24 r7:00000002 r6:b6f092d0 r5:df727a80 r4:df727a80
  30 [ 1462.207174] [<c0102890>] (SyS_write) from [<c000fa60>] (ret_fast_syscall+0x0/0x3c)
  31 [ 1462.214774]  r7:00000004 r6:ffffffff r5:00000000 r4:00000000
  32 [ 1462.220456] Code: bad PC value
  33 [ 1462.223560] ---[ end trace 676638a3a12c7a56 ]---
  34
  35 Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
  36 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  37 Fixes: 0f247626cbb ("usb: core: Introduce a USB port LED trigger")
  38 Cc: stable@vger.kernel.org # 4.9+
  39 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  40 ---
  41  drivers/usb/core/ledtrig-usbport.c | 7 +++----
  42  1 file changed, 3 insertions(+), 4 deletions(-)
  43
  44 --- a/drivers/usb/core/ledtrig-usbport.c
  45 +++ b/drivers/usb/core/ledtrig-usbport.c
  46 @@ -74,8 +74,7 @@ static void usbport_trig_update_count(st
  47
  48         usbport_data->count = 0;
  49         usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check);
  50 -       led_cdev->brightness_set(led_cdev,
  51 -                                usbport_data->count ? LED_FULL : LED_OFF);
  52 +       led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF);
  53  }
  54
  55  /***************************************
  56 @@ -228,12 +227,12 @@ static int usbport_trig_notify(struct no
  57         case USB_DEVICE_ADD:
  58                 usbport_trig_add_usb_dev_ports(usb_dev, usbport_data);
  59                 if (observed && usbport_data->count++ == 0)
  60 -                       led_cdev->brightness_set(led_cdev, LED_FULL);
  61 +                       led_set_brightness(led_cdev, LED_FULL);
  62                 return NOTIFY_OK;
  63         case USB_DEVICE_REMOVE:
  64                 usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev);
  65                 if (observed && --usbport_data->count == 0)
  66 -                       led_cdev->brightness_set(led_cdev, LED_OFF);
  67 +                       led_set_brightness(led_cdev, LED_OFF);
  68                 return NOTIFY_OK;
  69         }
  70