input: syz0 as /devices/virtual/input/input5 ====================================================== WARNING: possible circular locking dependency detected 6.15.0-next-20250605-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor190/5839 is trying to acquire lock: ffff88802771a870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_send drivers/input/misc/uinput.c:151 [inline] ffff88802771a870 (&newdev->mutex){+.+.}-{4:4}, at: uinput_request_submit+0x188/0x6f0 drivers/input/misc/uinput.c:182 but task is already holding lock: ffff8880284d90b0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:225 [inline] ffff8880284d90b0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x398/0xae0 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}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 class_mutex_constructor include/linux/mutex.h:225 [inline] input_ff_flush+0x5e/0x140 drivers/input/ff-core.c:231 input_flush_device+0xa6/0xd0 drivers/input/input.c:627 evdev_release+0xe1/0x800 drivers/input/evdev.c:435 __fput+0x449/0xa70 fs/file_table.c:467 fput_close_sync+0x119/0x200 fs/file_table.c:572 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&dev->mutex#2){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 class_mutex_intr_constructor include/linux/mutex.h:227 [inline] input_register_handle+0x18f/0x4c0 drivers/input/input.c:2653 kbd_connect+0xc3/0x140 drivers/tty/vt/keyboard.c:1580 input_attach_handler drivers/input/input.c:993 [inline] input_register_device+0xceb/0x10b0 drivers/input/input.c:2412 acpi_button_add+0x6b1/0xb50 drivers/acpi/button.c:621 acpi_device_probe+0xa5/0x2d0 drivers/acpi/bus.c:1076 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:657 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829 __driver_attach+0x452/0x700 drivers/base/dd.c:1215 bus_for_each_dev+0x230/0x2b0 drivers/base/bus.c:370 bus_add_driver+0x345/0x640 drivers/base/bus.c:678 driver_register+0x23a/0x320 drivers/base/driver.c:249 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 kernel_init+0x1d/0x1d0 init/main.c:1473 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (input_mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 class_mutex_intr_constructor include/linux/mutex.h:227 [inline] input_register_device+0xa74/0x10b0 drivers/input/input.c:2408 uinput_create_device+0x422/0x670 drivers/input/misc/uinput.c:365 uinput_ioctl_handler+0x3f0/0x1570 drivers/input/misc/uinput.c:918 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&newdev->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 uinput_request_send drivers/input/misc/uinput.c:151 [inline] uinput_request_submit+0x188/0x6f0 drivers/input/misc/uinput.c:182 uinput_dev_upload_effect+0x150/0x1e0 drivers/input/misc/uinput.c:257 input_ff_upload+0x5fc/0xae0 drivers/input/ff-core.c:148 evdev_do_ioctl drivers/input/evdev.c:1181 [inline] evdev_ioctl_handler+0x1644/0x1f10 drivers/input/evdev.c:1270 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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-executor190/5839: #0: ffff888141688118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_ioctl_handler+0x121/0x1f10 drivers/input/evdev.c:1261 #1: ffff8880284d90b0 (&ff->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:225 [inline] #1: ffff8880284d90b0 (&ff->mutex){+.+.}-{4:4}, at: input_ff_upload+0x398/0xae0 drivers/input/ff-core.c:122 stack backtrace: CPU: 1 UID: 0 PID: 5839 Comm: syz-executor190 Not tainted 6.15.0-next-20250605-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 uinput_request_send drivers/input/misc/uinput.c:151 [inline] uinput_request_submit+0x188/0x6f0 drivers/input/misc/uinput.c:182 uinput_dev_upload_effect+0x150/0x1e0 drivers/input/misc/uinput.c:257 input_ff_upload+0x5fc/0xae0 drivers/input/ff-core.c:148 evdev_do_ioctl drivers/input/evdev.c:1181 [inline] evdev_ioctl_handler+0x1644/0x1f10 drivers/input/evdev.c:1270 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f626c75e9b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff695b26c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f626c75e9b9 RDX: 0000200000000300 RSI: 0000000040304580 RDI: 0000000000000004 RBP: 00007f626c7d15f0 R08: 0000000000000006 R09: 0000000000000006 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000000001 R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001