====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz.0.0/5320 is trying to acquire lock: ffff8880408222c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:201 [inline] ffff8880408222c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_disconnect_device drivers/input/input.c:702 [inline] ffff8880408222c0 (&dev->mutex#2){+.+.}-{4:4}, at: __input_unregister_device+0x31/0x620 drivers/input/input.c:2219 but task is already holding lock: ffff88805260de20 (&hdev->ll_open_lock){+.+.}-{4:4}, at: hid_hw_open+0x28/0x170 drivers/hid/hid-core.c:2387 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&hdev->ll_open_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 hid_hw_open+0x28/0x170 drivers/hid/hid-core.c:2387 input_open_device+0x1eb/0x360 drivers/input/input.c:600 evdev_open_device drivers/input/evdev.c:391 [inline] evdev_open+0x3e0/0x5f0 drivers/input/evdev.c:478 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&dev->mutex#2){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 class_mutex_constructor include/linux/mutex.h:201 [inline] input_disconnect_device drivers/input/input.c:702 [inline] __input_unregister_device+0x31/0x620 drivers/input/input.c:2219 input_unregister_device+0xa3/0x100 drivers/input/input.c:2452 steam_client_ll_open+0x88/0xa0 drivers/hid/hid-steam.c:1121 hid_hw_open+0xe3/0x170 drivers/hid/hid-core.c:2392 hidraw_open+0x298/0x8e0 drivers/hid/hidraw.c:308 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->ll_open_lock); lock(&dev->mutex#2); lock(&hdev->ll_open_lock); lock(&dev->mutex#2); *** DEADLOCK *** 2 locks held by syz.0.0/5320: #0: ffffffff8fb0b8f0 (minors_rwsem){+.+.}-{4:4}, at: hidraw_open+0x93/0x8e0 drivers/hid/hidraw.c:294 #1: ffff88805260de20 (&hdev->ll_open_lock){+.+.}-{4:4}, at: hid_hw_open+0x28/0x170 drivers/hid/hid-core.c:2387 stack backtrace: CPU: 0 UID: 0 PID: 5320 Comm: syz.0.0 Not tainted 6.14.0-rc2-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 class_mutex_constructor include/linux/mutex.h:201 [inline] input_disconnect_device drivers/input/input.c:702 [inline] __input_unregister_device+0x31/0x620 drivers/input/input.c:2219 input_unregister_device+0xa3/0x100 drivers/input/input.c:2452 steam_client_ll_open+0x88/0xa0 drivers/hid/hid-steam.c:1121 hid_hw_open+0xe3/0x170 drivers/hid/hid-core.c:2392 hidraw_open+0x298/0x8e0 drivers/hid/hidraw.c:308 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7888f8b750 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44 RSP: 002b:00007f7889dd5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000014a042 RCX: 00007f7888f8b750 RDX: 000000000014a042 RSI: 00007f7889dd5c10 RDI: 00000000ffffff9c RBP: 00007f7889dd5c10 R08: 0000000000000000 R09: 0023776172646968 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f78891a5fa0 R15: 00007fff50664be8