INFO: task kworker/u8:15:1479 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:15   state:D stack:21856 pid:1479  tgid:1479  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue[  263.643938][   T38] Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x1681/0x54c0 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 io_schedule+0x80/0xe0 kernel/sched/core.c:8109
 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
 txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:376
 jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
 write_inode fs/fs-writeback.c:1584 [inline]
 __writeback_single_inode+0x75d/0x10e0 fs/fs-writeback.c:1827
 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
 wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
 wb_do_writeback fs/fs-writeback.c:2388 [inline]
 wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:5602 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:22040 pid:5602  tgid:5602  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x1681/0x54c0 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
 __writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
 sync_filesystem+0xa2/0x250 fs/sync.c:54
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 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:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee9540e017
RSP: 002b:00007ffcf4ec3b78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fee954a2120 RCX: 00007fee9540e017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcf4ec3c30
RBP: 00007ffcf4ec3c30 R08: 00007ffcf4ec4c30 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf4ec4cc0
R13: 00007fee954a2120 R14: 000000000001c3fc R15: 00007ffcf4ec4d00
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
8 locks held by kworker/u8:4/67:
4 locks held by kworker/u8:7/156:
5 locks held by kworker/u8:8/157:
2 locks held by kworker/u8:15/1479:
 #0: ffff88801f6b7938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff88801f6b7938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc9000684fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
 #1: ffffc9000684fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
7 locks held by kworker/u8:16/2310:
2 locks held by getty/5352:
 #0: ffff8880328000a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5600:
1 lock held by syz-executor/5602:
 #0: ffff8880630f60d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880630f60d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff8880630f60d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
1 lock held by udevd/5798:
3 locks held by udevd/5833:
1 lock held by syz.3.266/7377:
 #0: ffff8880630f60d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff8880630f60d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
4 locks held by syz-executor/7526:
1 lock held by syz.7.303/7538:
 #0: ffff88801fade0d0 (&type->s_umount_key#58/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
3 locks held by syz.5.305/7545:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 7b 6e 02 e9 43 c8 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 2b 2d 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc900001d7e20 EFLAGS: 00000246
RAX: 000000000001b9c3 RBX: ffffffff819953aa RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d603a74 RDI: ffffffff8ba74ce0
RBP: ffffc900001d7f10 R08: ffff8880b8933e9b R09: 1ffff110171267d3
R10: dffffc0000000000 R11: ffffed10171267d4 R12: 0000000000000001
R13: 1ffff11003a59000 R14: 0000000000000001 R15: 1ffff11003a59000
FS:  0000000000000000(0000) GS:ffff88812627a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c19488000 CR3: 0000000052604000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>