input: syz1 as /devices/virtual/input/input44 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.62/6765 is trying to acquire lock: ffff0000ca57d870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_send drivers/input/misc/uinput.c:151 [inline] ffff0000ca57d870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_submit+0x168/0x600 drivers/input/misc/uinput.c:182 but task is already holding lock: ffff0000ce5670b0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] ffff0000ce5670b0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x2f8/0x8e0 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:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 class_mutex_constructor include/linux/mutex.h:228 [inline] input_ff_flush+0x64/0x174 drivers/input/ff-core.c:231 uinput_dev_flush+0x30/0x4c drivers/input/misc/uinput.c:283 input_flush_device+0xb8/0x110 drivers/input/input.c:627 evdev_release+0xc8/0x608 drivers/input/evdev.c:435 __fput+0x340/0x75c fs/file_table.c:468 fput_close_sync+0x100/0x224 fs/file_table.c:573 __do_sys_close fs/open.c:1587 [inline] __se_sys_close fs/open.c:1572 [inline] __arm64_sys_close+0x7c/0x118 fs/open.c:1572 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #2 (&dev->mutex#2){+.+.}-{4:4}: __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:835 class_mutex_intr_constructor include/linux/mutex.h:230 [inline] input_register_handle+0x104/0x42c drivers/input/input.c:2653 kbd_connect+0xbc/0x134 drivers/tty/vt/keyboard.c:1580 input_attach_handler drivers/input/input.c:993 [inline] input_register_device+0xaa4/0xe68 drivers/input/input.c:2412 acpi_button_add+0x580/0x974 drivers/acpi/button.c:621 acpi_device_probe+0xa8/0x28c drivers/acpi/bus.c:1076 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x3b4/0x944 drivers/base/dd.c:659 __driver_probe_device+0x180/0x2d4 drivers/base/dd.c:801 driver_probe_device+0x78/0x330 drivers/base/dd.c:831 __driver_attach+0x3bc/0x61c drivers/base/dd.c:1217 bus_for_each_dev+0x204/0x290 drivers/base/bus.c:370 driver_attach+0x4c/0x5c drivers/base/dd.c:1235 bus_add_driver+0x2dc/0x5b0 drivers/base/bus.c:678 driver_register+0x220/0x30c drivers/base/driver.c:249 __acpi_bus_register_driver+0xc8/0x108 drivers/acpi/bus.c:1027 acpi_button_register_driver drivers/acpi/button.c:751 [inline] acpi_button_driver_init+0x9c/0xd8 drivers/acpi/button.c:760 do_one_initcall+0x250/0x990 init/main.c:1269 do_initcall_level+0x128/0x1c4 init/main.c:1331 do_initcalls+0x70/0xd0 init/main.c:1347 do_basic_setup+0x78/0x8c init/main.c:1366 kernel_init_freeable+0x268/0x39c init/main.c:1579 kernel_init+0x24/0x1dc init/main.c:1469 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 -> #1 (input_mutex){+.+.}-{4:4}: __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:835 class_mutex_intr_constructor include/linux/mutex.h:230 [inline] input_register_device+0x8b0/0xe68 drivers/input/input.c:2408 uinput_create_device+0x350/0x518 drivers/input/misc/uinput.c:365 uinput_ioctl_handler+0x404/0x1340 drivers/input/misc/uinput.c:918 uinput_ioctl+0x38/0x4c drivers/input/misc/uinput.c:1089 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:584 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 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+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:835 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+0x4d4/0x8e0 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:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:584 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 other info that might help us debug this: Chain exists of: &newdev->mutex --> &dev->mutex#2 --> &ff->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ff->mutex); lock(&dev->mutex#2); lock(&ff->mutex); lock(&newdev->mutex); *** DEADLOCK *** 2 locks held by syz.0.62/6765: #0: ffff0000d90e1118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_ioctl_handler+0x114/0x2214 drivers/input/evdev.c:1261 #1: ffff0000ce5670b0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #1: ffff0000ce5670b0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x2f8/0x8e0 drivers/input/ff-core.c:122 stack backtrace: CPU: 0 UID: 0 PID: 6765 Comm: syz.0.62 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 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+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_interruptible_nested+0x2c/0x38 kernel/locking/mutex.c:835 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+0x4d4/0x8e0 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:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:584 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596