On Fri, Sep 22, 2017 at 3:09 PM, Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote: > Hi Andrey, > > > On Friday 22 September 2017 05:16 PM, Andrey Konovalov wrote: >> >> 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. > > I have send a one patch to you. which will resolve this error. But my > question is why > hdpvr_probe() is failing. We need to find out. Could please share more > information and logs. The patch helps, thanks! hdpvr_probe() is failing, because I'm attaching a malicious USB device that pretends to be an hdpvr device, but doesn't have a bulk-in endpoint. [ 27.722420] gadgetfs: bound to dummy_udc driver [ 27.990245] usb 1-1: new full-speed USB device number 2 using dummy_hcd [ 28.010242] gadgetfs: connected [ 28.011732] gadgetfs: disconnected [ 28.230142] gadgetfs: connected [ 28.330313] usb 1-1: config 8 has an invalid interface number: 217 but max is 0 [ 28.331981] usb 1-1: config 8 has no interface number 0 [ 28.410315] usb 1-1: New USB device found, idVendor=2040, idProduct=4903 [ 28.411826] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=127 [ 28.413477] usb 1-1: SerialNumber: a [ 28.440134] gadgetfs: configuration #8 [ 28.467705] hdpvr 1-1:8.217: Could not find bulk-in endpoint [ 28.469024] hdpvr: probe of 1-1:8.217 failed with error -12 [ 29.446584] gadgetfs: disconnected [ 29.449634] usb 1-1: USB disconnect, device number 2 > > ~arvind > >> 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 > >
