INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:22928 pid:    9 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 __lock_metapage+0x1b8/0x390 fs/jfs/jfs_metapage.c:49
 lock_metapage fs/jfs/jfs_metapage.c:63 [inline]
 __get_metapage+0x43e/0x1060 fs/jfs/jfs_metapage.c:640
 diWrite+0x3f9/0x1600 fs/jfs/jfs_imap.c:639
 txCommit+0x843/0x5270 fs/jfs/jfs_txnmgr.c:1256
 jfs_commit_inode+0x2ec/0x520 fs/jfs/inode.c:114
 jfs_write_inode+0x141/0x220 fs/jfs/inode.c:138
 write_inode fs/fs-writeback.c:1505 [inline]
 __writeback_single_inode+0x6c4/0xda0 fs/fs-writeback.c:1715
 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940
 wb_writeback+0x44a/0xbc0 fs/fs-writeback.c:2114
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz-executor:4188 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21168 pid: 4188 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 wb_wait_for_completion+0x171/0x290 fs/fs-writeback.c:191
 __writeback_inodes_sb_nr+0x223/0x280 fs/fs-writeback.c:2701
 sync_filesystem+0x9f/0x220 fs/sync.c:54
 generic_shutdown_super+0x6b/0x300 fs/super.c:448
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4338855317
RSP: 002b:00007ffc719b7128 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f43388ea474 RCX: 00007f4338855317
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc719b71e0
RBP: 00007ffc719b71e0 R08: 00007ffc719b81e0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc719b8270
R13: 00007f43388ea474 R14: 0000000000025c3c R15: 00007ffc719b82b0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
 #0: ffff8881425c8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88805c5f4bc8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:108
1 lock held by ksoftirqd/1/20:
 #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
2 locks held by getty/3948:
 #0: ffff88802c5e5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4188:
 #0: ffff8880766500e0 (&type->s_umount_key#60){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
3 locks held by kworker/1:4/4196:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90002f1fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/1:14/4326:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90003d3fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
1 lock held by syz.5.264/6276:
 #0: ffffffff8c3238f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043
2 locks held by syz-executor/6565:
 #0: ffff8880202fe118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf1/0x780 block/bdev.c:911
 #1: ffff8880203f5468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xb50 drivers/block/loop.c:1366
4 locks held by syz.8.631/8996:
 #0: ffff88802a74c5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88807e860460 (sb_writers#37){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c571648 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x60/0x9e0 fs/nfsd/nfssvc.c:785
 #3: ffffffff8c3238f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043
1 lock held by sed/9037:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7e/0x80 kernel/kcov.c:295
Code: 8d 50 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a <c3> 90 48 8b 04 24 65 48 8b 0d 44 6e 89 7e 65 8b 15 45 6e 89 7e 81
RSP: 0018:ffffc90000da7900 EFLAGS: 00000046
RAX: ffffffff817f2800 RBX: ffffffff81493767 RCX: ffff888017a08000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000080000100 R08: ffffffff8d8b18ef R09: 1ffffffff1b1631d
R10: dffffc0000000000 R11: fffffbfff1b1631e R12: 0000000000000009
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000a06
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f42ec2cc7d0 CR3: 000000004a92c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_hardirqs_off+0x50/0x70 kernel/trace/trace_preemptirq.c:81
 raise_softirq+0x97/0x160 kernel/softirq.c:713
 invoke_rcu_core+0xae/0x210 kernel/rcu/tree.c:2810
 rcu_do_batch kernel/rcu/tree.c:2592 [inline]
 rcu_core+0xfcc/0x1650 kernel/rcu/tree.c:2763
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943
 smpboot_thread_fn+0x520/0x990 kernel/smpboot.c:164
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>