From 89778ba335e302a450932ce5b703c1ee6216e949 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Tue, 6 Dec 2016 00:39:33 +0100 Subject: [PATCH] usb: core: usbport: Use proper LED API to fix potential crash MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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] [] (usbport_trig_port_store [ledtrig_usbport]) from [] (dev_attr_store+0x20/0x2c) [ 1462.129826] r7:dcabc7c0 r6:dee0ff80 r5:00000002 r4:bf228164 [ 1462.135511] [] (dev_attr_store) from [] (sysfs_kf_write+0x48/0x4c) [ 1462.143459] r5:00000002 r4:c023f738 [ 1462.147049] [] (sysfs_kf_write) from [] (kernfs_fop_write+0xf8/0x1f8) [ 1462.155258] r5:00000002 r4:df4a1000 [ 1462.158850] [] (kernfs_fop_write) from [] (__vfs_write+0x34/0x120) [ 1462.166800] r10:00000000 r9:dee0e000 r8:c000fc24 r7:00000002 r6:dee0ff80 r5:c01689c0 [ 1462.174660] r4:df727a80 [ 1462.177204] [] (__vfs_write) from [] (vfs_write+0xac/0x170) [ 1462.184543] r9:dee0e000 r8:c000fc24 r7:dee0ff80 r6:b6f092d0 r5:df727a80 r4:00000002 [ 1462.192319] [] (vfs_write) from [] (SyS_write+0x4c/0xa8) [ 1462.199396] r9:dee0e000 r8:c000fc24 r7:00000002 r6:b6f092d0 r5:df727a80 r4:df727a80 [ 1462.207174] [] (SyS_write) from [] (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 Signed-off-by: Rafał Miłecki Fixes: 0f247626cbb ("usb: core: Introduce a USB port LED trigger") Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/ledtrig-usbport.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/usb/core/ledtrig-usbport.c +++ b/drivers/usb/core/ledtrig-usbport.c @@ -74,8 +74,7 @@ static void usbport_trig_update_count(st 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 no 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; }