syzbot

INFO: task syz.0.852:9391 blocked for more than 143 seconds.
      Not tainted 6.17.0-rc1-syzkaller-00214-g99bade344cfa #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.852       state:D stack:27304 pid:9391  tgid:9390  ppid:5858   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760
 comedi_device_attach+0xc6/0x720 drivers/comedi/drivers.c:969
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline]
 comedi_unlocked_ioctl+0x5ff/0x1020 drivers/comedi/comedi_fops.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93c798ebe9
RSP: 002b:00007f93c879c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f93c7bb5fa0 RCX: 00007f93c798ebe9
RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000005
RBP: 00007f93c7a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93c7bb6038 R14: 00007f93c7bb5fa0 R15: 00007ffcdcc6c748
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.17.0-rc1-syzkaller-00214-g99bade344cfa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11527 Comm: syz.3.1330 Not tainted 6.17.0-rc1-syzkaller-00214-g99bade344cfa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 8e 9d 70 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 06 d4 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 d5 32 c1 fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90002ff65b8 EFLAGS: 00000006
RAX: 1ffffffff33bde05 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000062e49 RDI: 0000000000062e4a
RBP: ffffc90002ff6790 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff854f0db0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99def3e0 R15: 0000000000000000
FS:  00007ff935bd56c0(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2e9be8 CR3: 0000000076bae000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 serial_port_in include/linux/serial_core.h:793 [inline]
 serial8250_console_write+0x584/0x1ba0 drivers/tty/serial/8250/8250_port.c:3360
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 __die_header+0x73/0x90 arch/x86/kernel/dumpstack.c:399
 __die+0x17/0x30 arch/x86/kernel/dumpstack.c:425
 die+0x2a/0x50 arch/x86/kernel/dumpstack.c:439
 do_trap_no_signal arch/x86/kernel/traps.c:206 [inline]
 do_trap+0x14a/0x3d0 arch/x86/kernel/traps.c:247
 do_error_trap+0x1c1/0x280 arch/x86/kernel/traps.c:267
 handle_invalid_op+0x34/0x40 arch/x86/kernel/traps.c:304
 exc_invalid_op+0x39/0x50 arch/x86/kernel/traps.c:397
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:ocfs2_write_cluster fs/ocfs2/aops.c:1159 [inline]
RIP: 0010:ocfs2_write_cluster_by_desc+0x1cc1/0x1cf0 fs/ocfs2/aops.c:1219
Code: 03 48 8d bc 24 10 02 00 00 48 c7 c6 a0 6e 9f 8d ba 6a 04 00 00 48 c7 c1 40 49 ca 8b e8 c8 51 1b 00 90 0f 0b e8 10 e0 26 fe 90 <0f> 0b e8 08 e0 26 fe 90 0f 0b e8 00 e0 26 fe 90 0f 0b e8 f8 df 26
RSP: 0018:ffffc90002ff6e60 EFLAGS: 00010283
RAX: ffffffff8398cb80 RBX: ffff888068770014 RCX: 0000000000080000
RDX: ffffc90026003000 RSI: 0000000000000949 RDI: 000000000000094a
RBP: ffffc90002ff7190 R08: ffff88806de7b1e3 R09: 1ffff1100dbcf63c
R10: dffffc0000000000 R11: ffffed100dbcf63d R12: ffff888047a74000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888068770014
 ocfs2_write_begin_nolock+0x31a3/0x4340 fs/ocfs2/aops.c:1796
 ocfs2_write_begin+0x1bb/0x310 fs/ocfs2/aops.c:1884
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
 ocfs2_file_write_iter+0x157a/0x1d10 fs/ocfs2/file.c:2469
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff93798ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff935bd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff937bb6180 RCX: 00007ff93798ebe9
RDX: 0000000000032600 RSI: 0000200000000100 RDI: 000000000000000b
RBP: 00007ff937a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff937bb6218 R14: 00007ff937bb6180 R15: 00007fff7e9ec408
 </TASK>