================================
WARNING: inconsistent lock state
syzkaller #0 Tainted: G L
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
syz.8.9459/432 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffff888032197068 (&dev->spinlock){?...}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff888032197068 (&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:348 [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:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [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: 25512
hardirqs last enabled at (25511): [<ffffffff8222f069>] seqcount_lockdep_reader_access+0x89/0xc0 include/linux/seqlock.h:75
hardirqs last disabled at (25512): [<ffffffff8bb2f7d3>] common_interrupt+0x13/0xe0 arch/x86/kernel/irq.c:326
softirqs last enabled at (25468): [<ffffffff8188e5ba>] __do_softirq kernel/softirq.c:660 [inline]
softirqs last enabled at (25468): [<ffffffff8188e5ba>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last enabled at (25468): [<ffffffff8188e5ba>] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:739
softirqs last disabled at (25439): [<ffffffff8188e5ba>] __do_softirq kernel/softirq.c:660 [inline]
softirqs last disabled at (25439): [<ffffffff8188e5ba>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (25439): [<ffffffff8188e5ba>] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:739
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.8.9459/432:
#0: ffff88801c2d2420 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88801c2d2420 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
#1: ffff888076a66c40 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff888076a66c40 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3456
stack backtrace:
CPU: 0 UID: 0 PID: 432 Comm: syz.8.9459 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
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:342 [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:stack_trace_consume_entry+0x20/0x280 kernel/stacktrace.c:86
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00 00 00 00 fc ff df 4c 8d 47 10 <4c> 89 c5 48 c1 ed 03 0f b6 44 15 00 84 c0 0f 85 09 01 00 00 44 8b
RSP: 0018:ffffc90005917158 EFLAGS: 00000292
RAX: ffffffff824142a0 RBX: ffffc90005917260 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff824142a0 RDI: ffffc90005917260
RBP: ffffc90005917230 R08: ffffc90005917270 R09: 0000000000000000
R10: ffffc900059171f8 R11: ffffffff81b1cb00 R12: ffff88803318bd00
R13: 1ffff1100663185e R14: ffffffff81b1cb00 R15: ffffc900059171a8
arch_stack_walk+0x10f/0x150 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x2418/0x24b0 mm/page_alloc.c:3924
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5211
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484
folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2503
shmem_alloc_folio mm/shmem.c:1933 [inline]
shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975
shmem_get_folio_gfp+0x4d4/0x1420 mm/shmem.c:2552
shmem_get_folio mm/shmem.c:2658 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3291
generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4320
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3466
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
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: 0033:0x7f9ca1b5cfce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f9ca2ad9da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9ca2ada6c0 RCX: 00007f9ca1b5cfce
RDX: 0000000001000000 RSI: 00007f9c97800000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f9ca2ad9ee0 R14: 00007f9ca2ad9ea0 R15: 00007f9c97800000
</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: f3 0f 1e fa endbr64
e: 55 push %rbp
f: 41 57 push %r15
11: 41 56 push %r14
13: 41 55 push %r13
15: 41 54 push %r12
17: 53 push %rbx
18: 48 83 ec 18 sub $0x18,%rsp
1c: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
23: fc ff df
26: 4c 8d 47 10 lea 0x10(%rdi),%r8
* 2a: 4c 89 c5 mov %r8,%rbp <-- trapping instruction
2d: 48 c1 ed 03 shr $0x3,%rbp
31: 0f b6 44 15 00 movzbl 0x0(%rbp,%rdx,1),%eax
36: 84 c0 test %al,%al
38: 0f 85 09 01 00 00 jne 0x147
3e: 44 rex.R
3f: 8b .byte 0x8b