syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.4282/23106 is trying to acquire lock:
ffff88814cce80f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_do_insn+0x38/0x3b0 drivers/comedi/kcomedilib/kcomedilib_main.c:73

but task is already holding lock:
ffff88814ccf28f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_unlocked_ioctl+0x17a/0x1210 drivers/comedi/comedi_fops.c:2161

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&dev->mutex#3);
  lock(&dev->mutex#3);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by syz.4.4282/23106:
 #0: ffff88814ccf28f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_unlocked_ioctl+0x17a/0x1210 drivers/comedi/comedi_fops.c:2161

stack backtrace:
CPU: 0 PID: 23106 Comm: syz.4.4282 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 __lock_acquire+0x123e/0x7d10 kernel/locking/lockdep.c:-1
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747
 comedi_do_insn+0x38/0x3b0 drivers/comedi/kcomedilib/kcomedilib_main.c:73
 comedi_dio_bitfield2+0x2ea/0x3c0 drivers/comedi/kcomedilib/kcomedilib_main.c:204
 bonding_dio_insn_bits+0x2c9/0x5e0 drivers/comedi/drivers/comedi_bond.c:100
 insn_rw_emulate_bits+0x332/0x5e0 drivers/comedi/drivers.c:641
 parse_insn+0x9f8/0x18a0 drivers/comedi/comedi_fops.c:1449
 do_insn_ioctl+0x170/0x530 drivers/comedi/comedi_fops.c:1674
 comedi_unlocked_ioctl+0xa36/0x1210 drivers/comedi/comedi_fops.c:2303
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ffb5cd9c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffb5dcb5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffb5d015fa0 RCX: 00007ffb5cd9c819
RDX: 0000200000000000 RSI: 000000008028640c RDI: 0000000000000003
RBP: 00007ffb5ce32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffb5d016038 R14: 00007ffb5d015fa0 R15: 00007ffff5feed48
 </TASK>