syzbot

input: syz1 as /devices/virtual/input/input5
======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc6-syzkaller-00227-g3d25a941ea50 #0 Not tainted
------------------------------------------------------
syz-executor328/5082 is trying to acquire lock:
ffff88802240b070 (&newdev->mutex){+.+.}-{3:3}, at: uinput_request_send drivers/input/misc/uinput.c:151 [inline]
ffff88802240b070 (&newdev->mutex){+.+.}-{3:3}, at: uinput_request_submit+0x19c/0x740 drivers/input/misc/uinput.c:182

but task is already holding lock:
ffff88802aed10b0 (&ff->mutex){+.+.}-{3:3}, at: input_ff_upload+0x3e4/0xb00 drivers/input/ff-core.c:120

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ff->mutex){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       input_ff_flush+0x5e/0x140 drivers/input/ff-core.c:240
       input_flush_device+0x9c/0xc0 drivers/input/input.c:686
       evdev_release+0xf9/0x7d0 drivers/input/evdev.c:444
       __fput+0x429/0x8a0 fs/file_table.c:422
       __do_sys_close fs/open.c:1556 [inline]
       __se_sys_close fs/open.c:1541 [inline]
       __x64_sys_close+0x7f/0x110 fs/open.c:1541
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&dev->mutex#2){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       input_register_handle+0x6d/0x3b0 drivers/input/input.c:2555
       kbd_connect+0xbf/0x130 drivers/tty/vt/keyboard.c:1589
       input_attach_handler drivers/input/input.c:1064 [inline]
       input_register_device+0xcfa/0x1090 drivers/input/input.c:2396
       acpi_button_add+0x6c6/0xb90 drivers/acpi/button.c:604
       acpi_device_probe+0xa5/0x2b0 drivers/acpi/bus.c:1057
       really_probe+0x2b8/0xad0 drivers/base/dd.c:656
       __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:798
       driver_probe_device+0x50/0x430 drivers/base/dd.c:828
       __driver_attach+0x45f/0x710 drivers/base/dd.c:1214
       bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:368
       bus_add_driver+0x347/0x620 drivers/base/bus.c:673
       driver_register+0x23a/0x320 drivers/base/driver.c:246
       do_one_initcall+0x248/0x880 init/main.c:1245
       do_initcall_level+0x157/0x210 init/main.c:1307
       do_initcalls+0x3f/0x80 init/main.c:1323
       kernel_init_freeable+0x435/0x5d0 init/main.c:1555
       kernel_init+0x1d/0x2b0 init/main.c:1444
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 (input_mutex){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       input_register_device+0xae5/0x1090 drivers/input/input.c:2389
       uinput_create_device+0x40e/0x630 drivers/input/misc/uinput.c:365
       uinput_ioctl_handler+0x48b/0x1770 drivers/input/misc/uinput.c:904
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&newdev->mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       uinput_request_send drivers/input/misc/uinput.c:151 [inline]
       uinput_request_submit+0x19c/0x740 drivers/input/misc/uinput.c:182
       uinput_dev_upload_effect+0x199/0x240 drivers/input/misc/uinput.c:257
       input_ff_upload+0x5df/0xb00 drivers/input/ff-core.c:150
       evdev_do_ioctl drivers/input/evdev.c:1183 [inline]
       evdev_ioctl_handler+0x17d0/0x21b0 drivers/input/evdev.c:1272
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       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-executor328/5082:
 #0: ffff88801abad110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_ioctl_handler+0x125/0x21b0 drivers/input/evdev.c:1263
 #1: ffff88802aed10b0 (&ff->mutex){+.+.}-{3:3}, at: input_ff_upload+0x3e4/0xb00 drivers/input/ff-core.c:120

stack backtrace:
CPU: 1 PID: 5082 Comm: syz-executor328 Not tainted 6.9.0-rc6-syzkaller-00227-g3d25a941ea50 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 uinput_request_send drivers/input/misc/uinput.c:151 [inline]
 uinput_request_submit+0x19c/0x740 drivers/input/misc/uinput.c:182
 uinput_dev_upload_effect+0x199/0x240 drivers/input/misc/uinput.c:257
 input_ff_upload+0x5df/0xb00 drivers/input/ff-core.c:150
 evdev_do_ioctl drivers/input/evdev.c:1183 [inline]
 evdev_ioctl_handler+0x17d0/0x21b0 drivers/input/evdev.c:1272
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf0598d269
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd88f2a448 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffd88f2a618 RCX: 00007fdf0598d269
RDX: 0000000020000300 RSI: 0000000040304580 RDI: 0000000000000004
RBP: 00007fdf05a00610 R08: 0000000000000000 R09: 00007ffd88f2a618
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd88f2a608 R14: 0000000000000001 R15: 0000000000000001
 </TASK>