============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.0.22258/25007 is trying to acquire lock: ffff88802f0f80f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_do_insn+0x38/0x3b0 drivers/comedi/kcomedilib/kcomedilib_main.c:73 but task is already holding lock: ffff88814c8a70f8 (&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.0.22258/25007: #0: ffff88814c8a70f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_unlocked_ioctl+0x17a/0x1210 drivers/comedi/comedi_fops.c:2161 stack backtrace: CPU: 0 PID: 25007 Comm: syz.0.22258 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: 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: 0033:0x7f397b99bf79 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:00007f397c867028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f397bc15fa0 RCX: 00007f397b99bf79 RDX: 0000200000000000 RSI: 000000008028640c RDI: 0000000000000003 RBP: 00007f397ba327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f397bc16038 R14: 00007f397bc15fa0 R15: 00007fff136183b8