================================
WARNING: inconsistent lock state
syzkaller #0 Tainted: G L
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
syz.9.24341/9322 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffff888031507068 (&dev->spinlock){?...}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
ffff888031507068 (&dev->spinlock){?...}-{3:3}, at: das16m1_interrupt+0x5e/0x180 drivers/comedi/drivers/das16m1.c:460
{HARDIRQ-ON-W} state was registered at:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:347 [inline]
waveform_ao_cancel+0x8d/0x120 drivers/comedi/drivers/comedi_test.c:628
do_cancel drivers/comedi/comedi_fops.c:818 [inline]
comedi_close+0x27e/0x5e0 drivers/comedi/comedi_fops.c:3036
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
irq event stamp: 444
hardirqs last enabled at (443): [<ffffffff8bbaef2e>] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242
hardirqs last disabled at (444): [<ffffffff8bbaa763>] common_interrupt+0x13/0xe0 arch/x86/kernel/irq.c:326
softirqs last enabled at (408): [<ffffffff81885edf>] __do_softirq kernel/softirq.c:660 [inline]
softirqs last enabled at (408): [<ffffffff81885edf>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last enabled at (408): [<ffffffff81885edf>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727
softirqs last disabled at (265): [<ffffffff81885edf>] __do_softirq kernel/softirq.c:660 [inline]
softirqs last disabled at (265): [<ffffffff81885edf>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (265): [<ffffffff81885edf>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&dev->spinlock);
<Interrupt>
lock(&dev->spinlock);
*** DEADLOCK ***
2 locks held by syz.9.24341/9322:
#0: ffff88807bc8d900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88807bc8d900 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x182/0x390 mm/gup.c:1942
#1: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#1: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#1: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:288
stack backtrace:
CPU: 0 UID: 0 PID: 9322 Comm: syz.9.24341 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<IRQ>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_usage_bug+0x28b/0x2e0 kernel/locking/lockdep.c:4042
valid_state kernel/locking/lockdep.c:4056 [inline]
mark_lock_irq+0x410/0x420 kernel/locking/lockdep.c:-1
mark_lock+0x115/0x190 kernel/locking/lockdep.c:4753
mark_usage kernel/locking/lockdep.c:4639 [inline]
__lock_acquire+0x661/0x2cf0 kernel/locking/lockdep.c:5191
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:341 [inline]
das16m1_interrupt+0x5e/0x180 drivers/comedi/drivers/das16m1.c:460
__handle_irq_event_percpu+0x227/0x9e0 kernel/irq/handle.c:209
handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263
handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
handle_irq arch/x86/kernel/irq.c:262 [inline]
call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
__common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:333
common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:326
</IRQ>
<TASK>
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:check_preemption_disabled+0x1d/0xe0 lib/smp_processor_id.c:53
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 57 13 87 07 65 8b 0d 4c 13 87 07 f7 c1 ff ff ff 7f 74 0c 5b <41> 5e 41 5f 5d c3 cc cc cc cc cc 9c 59 f7 c1 00 02 00 00 74 ea 65
RSP: 0018:ffffc90003a17688 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff8880b0d46660 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8c2a0ae0 RDI: ffffffff8c2a0aa0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90003a17a0c R11: fffff52000742f4a R12: 0000000000000000
R13: ffff8880b0d46678 R14: 0000000000000000 R15: 0000000000000001
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x57/0x2e0 kernel/locking/lockdep.c:5831
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:341 [inline]
pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402
do_anonymous_page mm/memory.c:5242 [inline]
do_pte_missing+0x9df/0x3750 mm/memory.c:4475
handle_pte_fault mm/memory.c:6317 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0x1bec/0x3310 mm/memory.c:6624
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x165b/0x29d0 mm/gup.c:1428
populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
__mm_populate+0x25f/0x390 mm/gup.c:1963
mm_populate include/linux/mm.h:3899 [inline]
vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd85b9c629
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:00007efd86a24028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007efd85e15fa0 RCX: 00007efd85b9c629
RDX: 0000000003000004 RSI: 0000000000c00000 RDI: 0000200000001000
RBP: 00007efd85c32b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000003032 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd85e16038 R14: 00007efd85e15fa0 R15: 00007ffd07299458
</TASK>
comedi comedi3: fifo overflow
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 55 push %rbp
e: 41 57 push %r15
10: 41 56 push %r14
12: 53 push %rbx
13: 65 8b 05 57 13 87 07 mov %gs:0x7871357(%rip),%eax # 0x7871371
1a: 65 8b 0d 4c 13 87 07 mov %gs:0x787134c(%rip),%ecx # 0x787136d
21: f7 c1 ff ff ff 7f test $0x7fffffff,%ecx
27: 74 0c je 0x35
29: 5b pop %rbx
* 2a: 41 5e pop %r14 <-- trapping instruction
2c: 41 5f pop %r15
2e: 5d pop %rbp
2f: c3 ret
30: cc int3
31: cc int3
32: cc int3
33: cc int3
34: cc int3
35: 9c pushf
36: 59 pop %rcx
37: f7 c1 00 02 00 00 test $0x200,%ecx
3d: 74 ea je 0x29
3f: 65 gs