INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.221' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.614001][ T12] usb 1-1: new high-speed USB device number 2 using dummy_hcd [ 27.974191][ T12] usb 1-1: config 0 interface 0 altsetting 0 endpoint 0x84 has an invalid bInterval 0, changing to 7 [ 27.985240][ T12] usb 1-1: New USB device found, idVendor=15c2, idProduct=0035, bcdDevice=d2.65 [ 27.994341][ T12] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 28.003733][ T12] usb 1-1: config 0 descriptor?? [ 28.047556][ T12] input: iMON Panel, Knob and Mouse(15c2:0035) as /devices/platform/dummy_hcd.0/usb1/1-1/1-1:0.0/input/input5 [ 28.284115][ T12] Registered IR keymap rc-imon-pad [ 28.504535][ T12] rc rc0: iMON Remote (15c2:0035) as /devices/platform/dummy_hcd.0/usb1/1-1/1-1:0.0/rc/rc0 [ 28.515256][ T12] input: iMON Remote (15c2:0035) as /devices/platform/dummy_hcd.0/usb1/1-1/1-1:0.0/rc/rc0/input6 [ 28.530098][ T12] imon 1-1:0.0: iMON device (15c2:0035, intf0) on usb<1:2> initialized [ 28.684233][ T1718] [ 28.686605][ T1718] ====================================================== [ 28.693602][ T1718] WARNING: possible circular locking dependency detected [ 28.700608][ T1718] 5.4.0-rc6+ #0 Not tainted [ 28.705092][ T1718] ------------------------------------------------------ [ 28.712099][ T1718] syz-executor532/1718 is trying to acquire lock: [ 28.718494][ T1718] ffffffff873ebfa0 (driver_lock#2){+.+.}, at: display_open+0x1f/0x1d0 [ 28.726658][ T1718] [ 28.726658][ T1718] but task is already holding lock: [ 28.734011][ T1718] ffffffff871ede88 (minor_rwsem){++++}, at: usb_open+0x23/0x270 [ 28.741636][ T1718] [ 28.741636][ T1718] which lock already depends on the new lock. [ 28.741636][ T1718] [ 28.752028][ T1718] [ 28.752028][ T1718] the existing dependency chain (in reverse order) is: [ 28.761137][ T1718] [ 28.761137][ T1718] -> #2 (minor_rwsem){++++}: [ 28.767902][ T1718] down_write+0x92/0x150 [ 28.772658][ T1718] usb_register_dev+0x131/0x670 [ 28.778039][ T1718] imon_probe+0x244d/0x2aed [ 28.783071][ T1718] usb_probe_interface+0x305/0x7a0 [ 28.788808][ T1718] really_probe+0x281/0x6d0 [ 28.793822][ T1718] driver_probe_device+0x104/0x210 [ 28.799463][ T1718] __device_attach_driver+0x1c2/0x220 [ 28.805345][ T1718] bus_for_each_drv+0x162/0x1e0 [ 28.810825][ T1718] __device_attach+0x217/0x360 [ 28.816115][ T1718] bus_probe_device+0x1e4/0x290 [ 28.821496][ T1718] device_add+0xae6/0x16f0 [ 28.826427][ T1718] usb_set_configuration+0xdf6/0x1670 [ 28.832327][ T1718] generic_probe+0x9d/0xd5 [ 28.837265][ T1718] usb_probe_device+0x99/0x100 [ 28.842539][ T1718] really_probe+0x281/0x6d0 [ 28.847554][ T1718] driver_probe_device+0x104/0x210 [ 28.853177][ T1718] __device_attach_driver+0x1c2/0x220 [ 28.859113][ T1718] bus_for_each_drv+0x162/0x1e0 [ 28.864492][ T1718] __device_attach+0x217/0x360 [ 28.869767][ T1718] bus_probe_device+0x1e4/0x290 [ 28.875133][ T1718] device_add+0xae6/0x16f0 [ 28.880057][ T1718] usb_new_device.cold+0x6a4/0xe79 [ 28.885710][ T1718] hub_event+0x1df8/0x3800 [ 28.890640][ T1718] process_one_work+0x92b/0x1530 [ 28.896261][ T1718] worker_thread+0x96/0xe20 [ 28.901270][ T1718] kthread+0x318/0x420 [ 28.905864][ T1718] ret_from_fork+0x24/0x30 [ 28.910783][ T1718] [ 28.910783][ T1718] -> #1 (&ictx->lock){+.+.}: [ 28.917541][ T1718] __mutex_lock+0x158/0x1360 [ 28.922639][ T1718] imon_probe+0xf0c/0x2aed [ 28.927585][ T1718] usb_probe_interface+0x305/0x7a0 [ 28.933210][ T1718] really_probe+0x281/0x6d0 [ 28.938238][ T1718] driver_probe_device+0x104/0x210 [ 28.943889][ T1718] __device_attach_driver+0x1c2/0x220 [ 28.949865][ T1718] bus_for_each_drv+0x162/0x1e0 [ 28.955314][ T1718] __device_attach+0x217/0x360 [ 28.960589][ T1718] bus_probe_device+0x1e4/0x290 [ 28.965959][ T1718] device_add+0xae6/0x16f0 [ 28.970890][ T1718] usb_set_configuration+0xdf6/0x1670 [ 28.976773][ T1718] generic_probe+0x9d/0xd5 [ 28.981698][ T1718] usb_probe_device+0x99/0x100 [ 28.986969][ T1718] really_probe+0x281/0x6d0 [ 28.991987][ T1718] driver_probe_device+0x104/0x210 [ 28.997608][ T1718] __device_attach_driver+0x1c2/0x220 [ 29.003501][ T1718] bus_for_each_drv+0x162/0x1e0 [ 29.008946][ T1718] __device_attach+0x217/0x360 [ 29.014218][ T1718] bus_probe_device+0x1e4/0x290 [ 29.019580][ T1718] device_add+0xae6/0x16f0 [ 29.024503][ T1718] usb_new_device.cold+0x6a4/0xe79 [ 29.030137][ T1718] hub_event+0x1df8/0x3800 [ 29.035078][ T1718] process_one_work+0x92b/0x1530 [ 29.040539][ T1718] worker_thread+0x96/0xe20 [ 29.045570][ T1718] kthread+0x318/0x420 [ 29.050146][ T1718] ret_from_fork+0x24/0x30 [ 29.055061][ T1718] [ 29.055061][ T1718] -> #0 (driver_lock#2){+.+.}: [ 29.061995][ T1718] __lock_acquire+0x1f74/0x3b60 [ 29.067357][ T1718] lock_acquire+0x127/0x320 [ 29.072368][ T1718] __mutex_lock+0x158/0x1360 [ 29.077474][ T1718] display_open+0x1f/0x1d0 [ 29.082400][ T1718] usb_open+0x1df/0x270 [ 29.087076][ T1718] chrdev_open+0x219/0x5c0 [ 29.091998][ T1718] do_dentry_open+0x494/0x1120 [ 29.097268][ T1718] path_openat+0x1430/0x3ff0 [ 29.102364][ T1718] do_filp_open+0x1a1/0x280 [ 29.107376][ T1718] do_sys_open+0x3c0/0x580 [ 29.112298][ T1718] do_syscall_64+0xb7/0x580 [ 29.117412][ T1718] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.123804][ T1718] [ 29.123804][ T1718] other info that might help us debug this: [ 29.123804][ T1718] [ 29.134019][ T1718] Chain exists of: [ 29.134019][ T1718] driver_lock#2 --> &ictx->lock --> minor_rwsem [ 29.134019][ T1718] [ 29.146155][ T1718] Possible unsafe locking scenario: [ 29.146155][ T1718] [ 29.153678][ T1718] CPU0 CPU1 [ 29.159041][ T1718] ---- ---- [ 29.164389][ T1718] lock(minor_rwsem); [ 29.168438][ T1718] lock(&ictx->lock); [ 29.175006][ T1718] lock(minor_rwsem); [ 29.181589][ T1718] lock(driver_lock#2); [ 29.185812][ T1718] [ 29.185812][ T1718] *** DEADLOCK *** [ 29.185812][ T1718] [ 29.193946][ T1718] 1 lock held by syz-executor532/1718: [ 29.199380][ T1718] #0: ffffffff871ede88 (minor_rwsem){++++}, at: usb_open+0x23/0x270 [ 29.207440][ T1718] [ 29.207440][ T1718] stack backtrace: [ 29.213323][ T1718] CPU: 0 PID: 1718 Comm: syz-executor532 Not tainted 5.4.0-rc6+ #0 [ 29.221193][ T1718] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.231235][ T1718] Call Trace: [ 29.234529][ T1718] dump_stack+0xca/0x13e [ 29.238762][ T1718] check_noncircular+0x32e/0x3e0 [ 29.243697][ T1718] ? profile_setup.cold+0xc1/0xc1 [ 29.248715][ T1718] ? print_circular_bug.isra.0+0x1e0/0x1e0 [ 29.254510][ T1718] ? usage_accumulate+0xa0/0xa0 [ 29.259360][ T1718] ? graph_lock+0x80/0x180 [ 29.263800][ T1718] ? hlock_class+0x120/0x120 [ 29.268394][ T1718] ? mark_lock+0xbc/0x1160 [ 29.272812][ T1718] ? find_first_zero_bit+0x94/0xb0 [ 29.277928][ T1718] __lock_acquire+0x1f74/0x3b60 [ 29.282793][ T1718] ? mark_held_locks+0xe0/0xe0 [ 29.287559][ T1718] ? hlock_class+0x120/0x120 [ 29.292137][ T1718] ? mark_lock+0xbc/0x1160 [ 29.296568][ T1718] ? find_first_zero_bit+0x94/0xb0 [ 29.301674][ T1718] lock_acquire+0x127/0x320 [ 29.306171][ T1718] ? display_open+0x1f/0x1d0 [ 29.310751][ T1718] __mutex_lock+0x158/0x1360 [ 29.315431][ T1718] ? display_open+0x1f/0x1d0 [ 29.320008][ T1718] ? mark_held_locks+0xe0/0xe0 [ 29.324781][ T1718] ? display_open+0x1f/0x1d0 [ 29.329358][ T1718] ? __lock_acquire+0x145e/0x3b60 [ 29.334378][ T1718] ? mutex_trylock+0x2c0/0x2c0 [ 29.339131][ T1718] ? lock_acquire+0x127/0x320 [ 29.343797][ T1718] ? usb_open+0x23/0x270 [ 29.348027][ T1718] ? down_read+0x115/0x420 [ 29.352432][ T1718] ? m_show+0x4f0/0x4f0 [ 29.356576][ T1718] ? display_open+0x1f/0x1d0 [ 29.361170][ T1718] display_open+0x1f/0x1d0 [ 29.365578][ T1718] ? usb_tx_callback+0x110/0x110 [ 29.370504][ T1718] usb_open+0x1df/0x270 [ 29.374674][ T1718] ? usb_devnode+0xa0/0xa0 [ 29.379098][ T1718] chrdev_open+0x219/0x5c0 [ 29.383522][ T1718] ? cdev_put.part.0+0x50/0x50 [ 29.388275][ T1718] do_dentry_open+0x494/0x1120 [ 29.393029][ T1718] ? cdev_put.part.0+0x50/0x50 [ 29.397780][ T1718] ? chmod_common+0x3c0/0x3c0 [ 29.402458][ T1718] ? inode_permission+0xbe/0x3a0 [ 29.407401][ T1718] path_openat+0x1430/0x3ff0 [ 29.411981][ T1718] ? save_stack+0x1b/0x80 [ 29.416309][ T1718] ? do_sys_open+0x294/0x580 [ 29.420886][ T1718] ? do_syscall_64+0xb7/0x580 [ 29.425558][ T1718] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.431614][ T1718] ? path_lookupat.isra.0+0x8d0/0x8d0 [ 29.436995][ T1718] ? __lock_acquire+0x145e/0x3b60 [ 29.442011][ T1718] do_filp_open+0x1a1/0x280 [ 29.446503][ T1718] ? may_open_dev+0xf0/0xf0 [ 29.451012][ T1718] ? __alloc_fd+0x46d/0x600 [ 29.455505][ T1718] ? _raw_spin_unlock+0x1f/0x30 [ 29.460341][ T1718] ? __alloc_fd+0x46d/0x600 [ 29.465205][ T1718] do_sys_open+0x3c0/0x580 [ 29.469611][ T1718] ? filp_open+0x70/0x70 [ 29.473841][ T1718] ? switch_fpu_return+0x1c2/0x430 [ 29.479042][ T1718] ? hrtimer_nanosleep+0x4f0/0x4f0 [ 29.484145][ T1718] ? trace_hardirqs_off_caller+0x55/0x1e0 [ 29.489852][ T1718] do_syscall_64+0xb7/0x580 [ 29.494362][ T1718] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.500258][ T1718] RIP: 0033:0x4016a0 [ 29.504139][ T1718] Code: 01 f0 ff ff 0f 83 00 0b 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 8d 24 2d 00 00 75 14 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 d4 0a 00 00 c3 48 83 ec 08 e8 3a 00 00 00 [ 29.523753][ T1718] RSP: 002b:00007ffc4d8d45d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 29.532154][ T1718] RAX: ffffffffffffffda RBX: 00000000004002c8