Re: usb/media/hdpvr: trying to register non-static key in hdpvr_probe

[Arvind Yadav <arvind.yadav.cs@gmail.com>]

Hi,

I have a doubt. Why we are calling flush_work in hdpvr_probe for every 
failure.
We are flushing work which is not defined yet.

Here, hdpvr_register_videodev() is responsible for setup and register a 
video device.
Also defining and initializing a worker. we are calling 
hdpvr_register_videodev() at last.
No need to flash any work here.

Please correct me, if I am wrong.

On Thursday 21 September 2017 09:09 PM, Andrey Konovalov wrote:
> Hi!
>
> I've got the following report while fuzzing the kernel with syzkaller.
>
> On commit ebb2c2437d8008d46796902ff390653822af6cc4 (Sep 18).
>
> INFO: trying to register non-static key.
> the code is fine but needs lockdep annotation.
> turning off the locking correctness validator.
> CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc1-42251-gebb2c2437d80 #215
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Workqueue: usb_hub_wq hub_event
> Call Trace:
>   __dump_stack lib/dump_stack.c:16
>   dump_stack+0x292/0x395 lib/dump_stack.c:52
>   register_lock_class+0x6c4/0x1a00 kernel/locking/lockdep.c:769
>   __lock_acquire+0x27e/0x4550 kernel/locking/lockdep.c:3385
>   lock_acquire+0x259/0x620 kernel/locking/lockdep.c:4002
>   flush_work+0xf0/0x8c0 kernel/workqueue.c:2886
>   hdpvr_probe+0x233/0x20d0 drivers/media/usb/hdpvr/hdpvr-core.c:400
>   usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
>   really_probe drivers/base/dd.c:413
>   driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
>   __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
>   bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
>   __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
>   device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
>   bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
>   device_add+0xd0b/0x1660 drivers/base/core.c:1835
>   usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932
>   generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174
>   usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266
>   really_probe drivers/base/dd.c:413
>   driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
>   __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
>   bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
>   __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
>   device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
>   bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
>   device_add+0xd0b/0x1660 drivers/base/core.c:1835
>   usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457
>   hub_port_connect drivers/usb/core/hub.c:4903
>   hub_port_connect_change drivers/usb/core/hub.c:5009
>   port_event drivers/usb/core/hub.c:5115
>   hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195
>   process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
>   worker_thread+0x221/0x1850 kernel/workqueue.c:2253
>   kthread+0x3a1/0x470 kernel/kthread.c:231
>   ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
> hdpvr: probe of 1-1:8.217 failed with error -12
~arvind