====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc3-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor535/337 is trying to acquire lock: ffffffff87b35f68 (driver_lock){+.+.}-{3:3}, at: display_open+0x1f/0x220 drivers/media/rc/imon.c:503 but task is already holding lock: ffffffff878ac990 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x270 drivers/usb/core/file.c:39 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (minor_rwsem){++++}-{3:3}: down_write+0x92/0x150 kernel/locking/rwsem.c:1531 usb_register_dev drivers/usb/core/file.c:187 [inline] usb_register_dev+0x19d/0x740 drivers/usb/core/file.c:156 imon_init_display drivers/media/rc/imon.c:2388 [inline] imon_probe+0x2459/0x2b60 drivers/media/rc/imon.c:2471 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:374 really_probe+0x291/0xc90 drivers/base/dd.c:525 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x28d/0x430 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xb09/0x1b40 drivers/base/core.c:2680 usb_set_configuration+0xf05/0x18a0 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0xba/0xf2 drivers/usb/core/generic.c:241 usb_probe_device+0xd9/0x250 drivers/usb/core/driver.c:272 really_probe+0x291/0xc90 drivers/base/dd.c:525 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x28d/0x430 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xb09/0x1b40 drivers/base/core.c:2680 usb_new_device.cold+0x71d/0xfd4 drivers/usb/core/hub.c:2554 hub_port_connect drivers/usb/core/hub.c:5208 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x2361/0x4390 drivers/usb/core/hub.c:5576 process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x82b/0x1120 kernel/workqueue.c:2417 kthread+0x392/0x470 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 -> #1 (&ictx->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10a0 kernel/locking/mutex.c:1103 imon_init_intf0 drivers/media/rc/imon.c:2233 [inline] imon_probe+0xfbf/0x2b60 drivers/media/rc/imon.c:2432 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:374 really_probe+0x291/0xc90 drivers/base/dd.c:525 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x28d/0x430 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xb09/0x1b40 drivers/base/core.c:2680 usb_set_configuration+0xf05/0x18a0 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0xba/0xf2 drivers/usb/core/generic.c:241 usb_probe_device+0xd9/0x250 drivers/usb/core/driver.c:272 really_probe+0x291/0xc90 drivers/base/dd.c:525 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x28d/0x430 drivers/base/dd.c:873 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xb09/0x1b40 drivers/base/core.c:2680 usb_new_device.cold+0x71d/0xfd4 drivers/usb/core/hub.c:2554 hub_port_connect drivers/usb/core/hub.c:5208 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x2361/0x4390 drivers/usb/core/hub.c:5576 process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x392/0x470 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 -> #0 (driver_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:2496 [inline] check_prevs_add kernel/locking/lockdep.c:2601 [inline] validate_chain kernel/locking/lockdep.c:3218 [inline] __lock_acquire+0x2ace/0x5530 kernel/locking/lockdep.c:4380 lock_acquire+0x183/0x940 kernel/locking/lockdep.c:4959 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10a0 kernel/locking/mutex.c:1103 display_open+0x1f/0x220 drivers/media/rc/imon.c:503 usb_open+0x1df/0x270 drivers/usb/core/file.c:48 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4ff/0x1170 fs/open.c:828 do_open fs/namei.c:3243 [inline] path_openat+0x192c/0x26b0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] ksys_open include/linux/syscalls.h:1388 [inline] __do_sys_open fs/open.c:1201 [inline] __se_sys_open fs/open.c:1199 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1199 do_syscall_64+0x50/0x90 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: driver_lock --> &ictx->lock --> minor_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(minor_rwsem); lock(&ictx->lock); lock(minor_rwsem); lock(driver_lock); *** DEADLOCK *** 1 lock held by syz-executor535/337: #0: ffffffff878ac990 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x270 drivers/usb/core/file.c:39 stack backtrace: CPU: 1 PID: 337 Comm: syz-executor535 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xf6/0x16e lib/dump_stack.c:118 check_noncircular+0x324/0x3e0 kernel/locking/lockdep.c:1827 check_prev_add kernel/locking/lockdep.c:2496 [inline] check_prevs_add kernel/locking/lockdep.c:2601 [inline] validate_chain kernel/locking/lockdep.c:3218 [inline] __lock_acquire+0x2ace/0x5530 kernel/locking/lockdep.c:4380 lock_acquire+0x183/0x940 kernel/locking/lockdep.c:4959 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x10a0 kernel/locking/mutex.c:1103 display_open+0x1f/0x220 drivers/media/rc/imon.c:503 usb_open+0x1df/0x270 drivers/usb/core/file.c:48 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4ff/0x1170 fs/open.c:828 do_open fs/namei.c:3243 [inline] path_openat+0x192c/0x26b0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] ksys_open include/linux/syscalls.h:1388 [inline] __do_sys_open fs/open.c:1201 [inline] __se_sys_open fs/open.c:1199 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1199 do_syscall_64+0x50/0x90 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4018e0 Code: Bad RIP value. RSP: 002b:00007ffe6aedc388 EFLAGS: 00000246 ORIG_RAX: 00