On Fri, Sep 22, 2017 at 9:41 AM, Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote: > 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. Hi Arvind, I believe you're right, no need to call flush_work() before dev->worker is initialized. Could you send a fix? I'm able to reproduce the issue, so I can test your patches if needed. Thanks! > > > 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
