input: syz1 as /devices/virtual/input/input104 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.18/6925 is trying to acquire lock: ffff0000d6f82870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_send drivers/input/misc/uinput.c:151 [inline] ffff0000d6f82870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_submit+0x168/0x600 drivers/input/misc/uinput.c:182 but task is already holding lock: ffff0000d4768cb0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] ffff0000d4768cb0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x2f0/0x924 drivers/input/ff-core.c:122 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ff->mutex){+.+.}-{4:4}: __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:614 __mutex_lock kernel/locking/mutex.c:776 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:828 class_mutex_constructor include/linux/mutex.h:253 [inline] input_ff_upload+0x2f0/0x924 drivers/input/ff-core.c:122 evdev_do_ioctl drivers/input/evdev.c:1181 [inline] evdev_ioctl_handler+0x18bc/0x2214 drivers/input/evdev.c:1270 evdev_ioctl+0x38/0x4c drivers/input/evdev.c:1279 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #2 (&evdev->mutex){+.+.}-{4:4}: __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:614 __mutex_lock kernel/locking/mutex.c:776 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:828 evdev_mark_dead drivers/input/evdev.c:1311 [inline] evdev_cleanup+0x30/0x15c drivers/input/evdev.c:1320 evdev_disconnect+0x50/0xb4 drivers/input/evdev.c:1404 __input_unregister_device+0x338/0x5cc drivers/input/input.c:2189 input_unregister_device+0xa8/0xf4 drivers/input/input.c:2418 uinput_destroy_device+0x598/0x774 drivers/input/misc/uinput.c:299 uinput_release+0x44/0x60 drivers/input/misc/uinput.c:758 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x10c/0x18c kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:242 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_svc+0x17c/0x26c arch/arm64/kernel/entry-common.c:725 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #1 (input_mutex){+.+.}-{4:4}: __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:614 __mutex_lock kernel/locking/mutex.c:776 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:851 class_mutex_intr_constructor include/linux/mutex.h:255 [inline] input_register_device+0x8b0/0xe90 drivers/input/input.c:2374 uinput_create_device+0x350/0x518 drivers/input/misc/uinput.c:365 uinput_ioctl_handler+0x404/0x1340 drivers/input/misc/uinput.c:919 uinput_ioctl+0x38/0x4c drivers/input/misc/uinput.c:1090 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #0 (&newdev->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:614 __mutex_lock kernel/locking/mutex.c:776 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:851 uinput_request_send drivers/input/misc/uinput.c:151 [inline] uinput_request_submit+0x168/0x600 drivers/input/misc/uinput.c:182 uinput_dev_upload_effect+0x130/0x1c0 drivers/input/misc/uinput.c:257 input_ff_upload+0x4cc/0x924 drivers/input/ff-core.c:148 evdev_do_ioctl drivers/input/evdev.c:1181 [inline] evdev_ioctl_handler+0x18bc/0x2214 drivers/input/evdev.c:1270 evdev_ioctl+0x38/0x4c drivers/input/evdev.c:1279 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 other info that might help us debug this: Chain exists of: &newdev->mutex --> &evdev->mutex --> &ff->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ff->mutex); lock(&evdev->mutex); lock(&ff->mutex); lock(&newdev->mutex); *** DEADLOCK *** 2 locks held by syz.1.18/6925: #0: ffff0000cb8ec118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_ioctl_handler+0x114/0x2214 drivers/input/evdev.c:1261 #1: ffff0000d4768cb0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff0000d4768cb0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x2f0/0x924 drivers/input/ff-core.c:122 stack backtrace: CPU: 0 UID: 0 PID: 6925 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2043 check_noncircular+0x154/0x174 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:614 __mutex_lock kernel/locking/mutex.c:776 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:851 uinput_request_send drivers/input/misc/uinput.c:151 [inline] uinput_request_submit+0x168/0x600 drivers/input/misc/uinput.c:182 uinput_dev_upload_effect+0x130/0x1c0 drivers/input/misc/uinput.c:257 input_ff_upload+0x4cc/0x924 drivers/input/ff-core.c:148 evdev_do_ioctl drivers/input/evdev.c:1181 [inline] evdev_ioctl_handler+0x18bc/0x2214 drivers/input/evdev.c:1270 evdev_ioctl+0x38/0x4c drivers/input/evdev.c:1279 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596