INFO: task syz-executor:5864 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21544 pid:5864  tgid:5864  ppid:1      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
 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
 __writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2748
 sync_filesystem+0xa3/0x230 fs/sync.c:54
 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2576
 deactivate_locked_super+0xb9/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c7cf8ff17
RSP: 002b:00007fff3bf05668 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f6c7d011c05 RCX: 00007f6c7cf8ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff3bf05720
RBP: 00007fff3bf05720 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff3bf067b0
R13: 00007f6c7d011c05 R14: 000000000001ae61 R15: 00007fff3bf067f0
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #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:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 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: 5234 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rseq_update_cpu_node_id kernel/rseq.c:163 [inline]
RIP: 0010:__rseq_handle_notify_resume+0x1bd/0x11f0 kernel/rseq.c:442
Code: 85 0c 0d 00 00 41 8b 3f e9 8e 02 00 00 e8 2b 36 ca ff 48 8b 44 24 20 48 8d 98 70 15 00 00 49 89 de 49 c1 ee 03 43 80 3c 26 00 <74> 08 48 89 df e8 d9 df 2d 00 4d 8b a7 70 15 00 00 65 8b 3d 5f b7
RSP: 0018:ffffc90003107da0 EFLAGS: 00000246
RAX: ffff88807c7e3c00 RBX: ffff88807c7e5170 RCX: ffff88807c7e3c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003107eb0 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90003107e20 R11: fffff52000620fc8 R12: dffffc0000000000
R13: ffffc90003107fc8 R14: 1ffff1100f8fca2e R15: ffff88807c7e3c00
FS:  00007f71163d1880(0000) GS:ffff888125aff000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 000000007bca2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:62 [inline]
 exit_to_user_mode_loop+0xc2/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7115d11ad7
Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007fff400ed038 EFLAGS: 00000297 ORIG_RAX: 0000000000000005
RAX: 0000000000000000 RBX: 00005618ed155280 RCX: 00007f7115d11ad7
RDX: 00007f7115defea0 RSI: 00007fff400ed040 RDI: 000000000000000c
RBP: 00007f7115defff0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 000000000000000a
R13: 0000000000003fff R14: 0000000000000000 R15: 00005618ed155280
 </TASK>
vkms_vblank_simulate: vblank timer overrun