syzbot

input: Steam Controller as /devices/platform/dummy_hcd.2/usb3/3-1/3-1:0.0/0003:28DE:1102.0015/input/input31
======================================================
WARNING: possible circular locking dependency detected
6.1.130-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.2652/15186 is trying to acquire lock:
ffffffff8e03d668 (input_mutex){+.+.}-{3:3}, at: input_register_device+0xb54/0x1250 drivers/input/input.c:2463

but task is already holding lock:
ffff888061b81e18 (&hdev->ll_open_lock){+.+.}-{3:3}, at: hid_hw_close+0x2c/0xd0 drivers/hid/hid-core.c:2364

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&hdev->ll_open_lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       hid_hw_open+0x24/0x160 drivers/hid/hid-core.c:2338
       input_open_device+0x188/0x2d0 drivers/input/input.c:650
       mousedev_open_device+0xc3/0x160 drivers/input/mousedev.c:430
       mousedev_open+0x2c9/0x470 drivers/input/mousedev.c:556
       chrdev_open+0x54a/0x630 fs/char_dev.c:414
       do_dentry_open+0x7f9/0x10f0 fs/open.c:882
       do_open fs/namei.c:3626 [inline]
       path_openat+0x2644/0x2e60 fs/namei.c:3783
       do_filp_open+0x230/0x480 fs/namei.c:3810
       do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&dev->mutex#2){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       input_register_handle+0x69/0x3a0 drivers/input/input.c:2629
       kbd_connect+0xbb/0x120 drivers/tty/vt/keyboard.c:1589
       input_attach_handler drivers/input/input.c:1060 [inline]
       input_register_device+0xd65/0x1250 drivers/input/input.c:2470
       acpi_button_add+0x62a/0x9f0 drivers/acpi/button.c:570
       acpi_device_probe+0xa0/0x2f0 drivers/acpi/bus.c:1023
       really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
       __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
       driver_probe_device+0x50/0x420 drivers/base/dd.c:815
       __driver_attach+0x458/0x6f0 drivers/base/dd.c:1201
       bus_for_each_dev+0x17c/0x1f0 drivers/base/bus.c:303
       bus_add_driver+0x334/0x600 drivers/base/bus.c:620
       driver_register+0x2bf/0x3a0 drivers/base/driver.c:246
       do_one_initcall+0x265/0x8f0 init/main.c:1298
       do_initcall_level+0x157/0x207 init/main.c:1371
       do_initcalls+0x49/0x86 init/main.c:1387
       kernel_init_freeable+0x45c/0x60f init/main.c:1626
       kernel_init+0x19/0x290 init/main.c:1514
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 (input_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       input_register_device+0xb54/0x1250 drivers/input/input.c:2463
       steam_input_register+0x96b/0xbf0 drivers/hid/hid-steam.c:469
       hid_hw_close+0xa4/0xd0 drivers/hid/hid-core.c:2366
       drop_ref drivers/hid/hidraw.c:343 [inline]
       hidraw_release+0x46d/0x6c0 drivers/hid/hidraw.c:367
       __fput+0x3f6/0x8d0 fs/file_table.c:320
       task_work_run+0x246/0x300 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
       syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
       do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  input_mutex --> &dev->mutex#2 --> &hdev->ll_open_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&hdev->ll_open_lock);
                               lock(&dev->mutex#2);
                               lock(&hdev->ll_open_lock);
  lock(input_mutex);

 *** DEADLOCK ***

2 locks held by syz.2.2652/15186:
 #0: ffffffff8e3bd750 (minors_rwsem){++++}-{3:3}, at: hidraw_release+0x70/0x6c0 drivers/hid/hidraw.c:355
 #1: ffff888061b81e18 (&hdev->ll_open_lock){+.+.}-{3:3}, at: hid_hw_close+0x2c/0xd0 drivers/hid/hid-core.c:2364

stack backtrace:
CPU: 0 PID: 15186 Comm: syz.2.2652 Not tainted 6.1.130-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 input_register_device+0xb54/0x1250 drivers/input/input.c:2463
 steam_input_register+0x96b/0xbf0 drivers/hid/hid-steam.c:469
 hid_hw_close+0xa4/0xd0 drivers/hid/hid-core.c:2366
 drop_ref drivers/hid/hidraw.c:343 [inline]
 hidraw_release+0x46d/0x6c0 drivers/hid/hidraw.c:367
 __fput+0x3f6/0x8d0 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f47bb78d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff59303118 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f47bb9a7ba0 RCX: 00007f47bb78d169
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f47bb9a7ba0 R08: 00000000000001cc R09: 000000135930340f
R10: 00000000003ffc10 R11: 0000000000000246 R12: 0000000000118479
R13: 00007f47bb9a6080 R14: ffffffffffffffff R15: 00007fff59303230
 </TASK>