WARNING: possible recursive locking detected 5.4.0-syzkaller #0 Not tainted -------------------------------------------- kworker/0:4/3278 is trying to acquire lock: ffff8881d41b4208 (i2c_register_adapter){+.+.}, at: i2c_lock_bus include/linux/i2c.h:767 [inline] ffff8881d41b4208 (i2c_register_adapter){+.+.}, at: __i2c_lock_bus_helper drivers/i2c/i2c-core.h:44 [inline] ffff8881d41b4208 (i2c_register_adapter){+.+.}, at: i2c_transfer+0x1d3/0x3b0 drivers/i2c/i2c-core-base.c:2015 but task is already holding lock: ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: i2c_lock_bus include/linux/i2c.h:767 [inline] ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: __i2c_lock_bus_helper drivers/i2c/i2c-core.h:44 [inline] ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: i2c_transfer+0x1d3/0x3b0 drivers/i2c/i2c-core-base.c:2015 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(i2c_register_adapter); lock(i2c_register_adapter); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/0:4/3278: #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d93fa528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2235 #1: ffff8881aece7dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2239 #2: ffff8881d55c3200 (&dev->mutex){....}, at: device_lock include/linux/device.h:1493 [inline] #2: ffff8881d55c3200 (&dev->mutex){....}, at: hub_event+0x1b2/0x3860 drivers/usb/core/hub.c:5498 #3: ffff8881d7040200 (&dev->mutex){....}, at: device_lock include/linux/device.h:1493 [inline] #3: ffff8881d7040200 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881baa14190 (&dev->mutex){....}, at: device_lock include/linux/device.h:1493 [inline] #4: ffff8881baa14190 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #5: ffff8881cfeee180 (&dev->mutex){....}, at: device_lock include/linux/device.h:1493 [inline] #5: ffff8881cfeee180 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #6: ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: i2c_lock_bus include/linux/i2c.h:767 [inline] #6: ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: __i2c_lock_bus_helper drivers/i2c/i2c-core.h:44 [inline] #6: ffff8881c17f05c0 (i2c_register_adapter){+.+.}, at: i2c_transfer+0x1d3/0x3b0 drivers/i2c/i2c-core-base.c:2015 stack backtrace: CPU: 0 PID: 3278 Comm: kworker/0:4 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xef/0x16e lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:2371 [inline] check_deadlock kernel/locking/lockdep.c:2412 [inline] validate_chain kernel/locking/lockdep.c:2955 [inline] __lock_acquire.cold+0x114/0x288 kernel/locking/lockdep.c:3955 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4485 __rt_mutex_lock kernel/locking/rtmutex.c:1471 [inline] rt_mutex_lock_nested+0x3e/0x60 kernel/locking/rtmutex.c:1484 i2c_lock_bus include/linux/i2c.h:767 [inline] __i2c_lock_bus_helper drivers/i2c/i2c-core.h:44 [inline] i2c_transfer+0x1d3/0x3b0 drivers/i2c/i2c-core-base.c:2015 tc90522_master_xfer.part.0+0x65c/0xbf0 drivers/media/dvb-frontends/tc90522.c:708 tc90522_master_xfer+0x35/0x4e drivers/media/dvb-frontends/tc90522.c:643 __i2c_transfer drivers/i2c/i2c-core-base.c:1958 [inline] __i2c_transfer+0x49d/0x1620 drivers/i2c/i2c-core-base.c:1923 i2c_transfer drivers/i2c/i2c-core-base.c:2019 [inline] i2c_transfer+0x1e6/0x3b0 drivers/i2c/i2c-core-base.c:1990 dvb_pll_attach+0x228/0x850 drivers/media/dvb-frontends/dvb-pll.c:816 dvb_pll_probe+0xfe/0x174 drivers/media/dvb-frontends/dvb-pll.c:884 i2c_device_probe+0x74e/0xa40 drivers/i2c/i2c-core-base.c:389 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1480/0x1c20 drivers/base/core.c:2487 i2c_new_client_device+0x57f/0x9b0 drivers/i2c/i2c-core-base.c:777 i2c_new_device+0x19/0x50 drivers/i2c/i2c-core-base.c:820 dvb_module_probe+0xf9/0x220 drivers/media/dvb-core/dvbdev.c:986 friio_tuner_attach+0x12b/0x1d0 drivers/media/usb/dvb-usb-v2/gl861.c:457 dvb_usbv2_adapter_frontend_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:676 [inline] dvb_usbv2_adapter_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:805 [inline] dvb_usbv2_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:866 [inline] dvb_usbv2_probe.cold+0x2550/0x25d7 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:981 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1480/0x1c20 drivers/base/core.c:2487 usb_set_configuration+0xe67/0x1740 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1480/0x1c20 drivers/base/core.c:2487 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537 hub_port_connect drivers/usb/core/hub.c:5184 [inline] hub_port_connect_change drivers/usb/core/hub.c:5324 [inline] port_event drivers/usb/core/hub.c:5470 [inline] hub_event+0x1e59/0x3860 drivers/usb/core/hub.c:5552 process_one_work+0x92b/0x1530 kernel/workqueue.c:2264 process_scheduled_works kernel/workqueue.c:2326 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 dvb_pll: probe of 1-0060 failed with error -12 usb 1-1: USB disconnect, device number 22 usb 1-1: new high-speed USB device number 23 using dummy_hcd usb 1-1: New USB device found, idVendor=20b7, idProduct=1540, bcdDevice=ef.8f usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 usb 1-1: config 0 descriptor?? usb 1-1: atusb_control_msg: req 0x10 val 0x0 idx 0x0, error -71 usb 1-1: Firmware version (0.0) predates our first public release. usb 1-1: Please update to version 0.2 or newer usb 1-1: atusb_probe: initialization failed, error = -71 atusb: probe of 1-1:0.0 failed with error -71 usb 1-1: USB disconnect, device number 23 usb 1-1: new high-speed USB device number 24 using dummy_hcd usb 1-1: device descriptor read/all, error -71 usb 1-1: new high-speed USB device number 25 using dummy_hcd usb 1-1: Using ep0 maxpacket: 16 usb 1-1: config 1 interface 0 altsetting 0 has 2 endpoint descriptors, different from the interface descriptor's value: 1 usb 1-1: string descriptor 0 read error: -22 usb 1-1: New USB device found, idVendor=17ef, idProduct=60a3, bcdDevice= 0.40 usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usbhid 1-1:1.0: can't add hid device: -71 usbhid: probe of 1-1:1.0 failed with error -71 usb 1-1: USB disconnect, device number 25 usb 1-1: new high-speed USB device number 26 using dummy_hcd usb 1-1: device descriptor read/64, error -71 usb 1-1: Using ep0 maxpacket: 8 usb 1-1: config 118 has an invalid descriptor of length 0, skipping remainder of the config usb 1-1: config 118 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 7 usb 1-1: New USB device found, idVendor=2400, idProduct=4200, bcdDevice=42.ef usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 hub 1-1:118.0: bad descriptor, ignoring hub hub: probe of 1-1:118.0 failed with error -5 cdc_wdm 1-1:118.0: cdc-wdm0: USB WDM device usb 6-1: new high-speed USB device number 12 using dummy_hcd usb 6-1: Using ep0 maxpacket: 8 usb 6-1: New USB device found, idVendor=0421, idProduct=0a54, bcdDevice=67.92 usb 6-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 usb 6-1: config 0 descriptor?? cdc_phonet 6-1:0.0: skipping garbage cdc_phonet: probe of 6-1:0.0 failed with error -22