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authorRafał Miłecki <rafal@milecki.pl>2016-12-06 00:39:33 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-06 10:40:11 +0100
commiteab169397ad687e69b3bde3547a1fd37e7f81194 (patch)
tree90a597f89140f789085299c7a18916cc95511089 /drivers/usb/core
parent32a35351b7ec93947efb394f252d9ad714a04f18 (diff)
usb: core: usbport: Use proper LED API to fix potential crash
commit 89778ba335e302a450932ce5b703c1ee6216e949 upstream. Calling brightness_set manually isn't safe as some LED drivers don't implement this callback. The best idea is to just use a proper helper which will fallback to the brightness_set_blocking callback if needed. This fixes: [ 1461.761528] Unable to handle kernel NULL pointer dereference at virtual address 00000000 (...) [ 1462.117049] Backtrace: [ 1462.119521] [<bf228164>] (usbport_trig_port_store [ledtrig_usbport]) from [<c023f758>] (dev_attr_store+0x20/0x2c) [ 1462.129826] r7:dcabc7c0 r6:dee0ff80 r5:00000002 r4:bf228164 [ 1462.135511] [<c023f738>] (dev_attr_store) from [<c0169310>] (sysfs_kf_write+0x48/0x4c) [ 1462.143459] r5:00000002 r4:c023f738 [ 1462.147049] [<c01692c8>] (sysfs_kf_write) from [<c0168ab8>] (kernfs_fop_write+0xf8/0x1f8) [ 1462.155258] r5:00000002 r4:df4a1000 [ 1462.158850] [<c01689c0>] (kernfs_fop_write) from [<c0100c78>] (__vfs_write+0x34/0x120) [ 1462.166800] r10:00000000 r9:dee0e000 r8:c000fc24 r7:00000002 r6:dee0ff80 r5:c01689c0 [ 1462.174660] r4:df727a80 [ 1462.177204] [<c0100c44>] (__vfs_write) from [<c0101ae4>] (vfs_write+0xac/0x170) [ 1462.184543] r9:dee0e000 r8:c000fc24 r7:dee0ff80 r6:b6f092d0 r5:df727a80 r4:00000002 [ 1462.192319] [<c0101a38>] (vfs_write) from [<c01028dc>] (SyS_write+0x4c/0xa8) [ 1462.199396] r9:dee0e000 r8:c000fc24 r7:00000002 r6:b6f092d0 r5:df727a80 r4:df727a80 [ 1462.207174] [<c0102890>] (SyS_write) from [<c000fa60>] (ret_fast_syscall+0x0/0x3c) [ 1462.214774] r7:00000004 r6:ffffffff r5:00000000 r4:00000000 [ 1462.220456] Code: bad PC value [ 1462.223560] ---[ end trace 676638a3a12c7a56 ]--- Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Fixes: 0f247626cbb ("usb: core: Introduce a USB port LED trigger") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/ledtrig-usbport.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/usb/core/ledtrig-usbport.c b/drivers/usb/core/ledtrig-usbport.c
index 3ed5162677ad..1713248ab15a 100644
--- a/drivers/usb/core/ledtrig-usbport.c
+++ b/drivers/usb/core/ledtrig-usbport.c
@@ -74,8 +74,7 @@ static void usbport_trig_update_count(struct usbport_trig_data *usbport_data)
usbport_data->count = 0;
usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check);
- led_cdev->brightness_set(led_cdev,
- usbport_data->count ? LED_FULL : LED_OFF);
+ led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF);
}
/***************************************
@@ -228,12 +227,12 @@ static int usbport_trig_notify(struct notifier_block *nb, unsigned long action,
case USB_DEVICE_ADD:
usbport_trig_add_usb_dev_ports(usb_dev, usbport_data);
if (observed && usbport_data->count++ == 0)
- led_cdev->brightness_set(led_cdev, LED_FULL);
+ led_set_brightness(led_cdev, LED_FULL);
return NOTIFY_OK;
case USB_DEVICE_REMOVE:
usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev);
if (observed && --usbport_data->count == 0)
- led_cdev->brightness_set(led_cdev, LED_OFF);
+ led_set_brightness(led_cdev, LED_OFF);
return NOTIFY_OK;
}