INFO: task kworker/u8:18:6463 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:18   state:D stack:22432 pid:6463  tgid:6463  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x14bc/0x5030 kernel/sched/core.c:6864
 __schedule_loop kernel/sched/core.c:6946 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6961
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018
 __mutex_lock_common kernel/locking/mutex.c:686 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770
 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
 write_inode fs/fs-writeback.c:1582 [inline]
 __writeback_single_inode+0x7e1/0x12f0 fs/fs-writeback.c:1802
 writeback_sb_inodes+0x984/0x1950 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
 wb_writeback+0x43f/0xb10 fs/fs-writeback.c:2218
 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
 wb_do_writeback fs/fs-writeback.c:2375 [inline]
 wb_workfn+0xaf2/0xef0 fs/fs-writeback.c:2403
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/36:
2 locks held by getty/5588:
 #0: ffff888034a850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/u8:18/6463:
 #0: ffff8881416ae948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
 #1: ffffc9001ab2fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
 #2: ffff88807dfd80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff8880488101c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
3 locks held by kworker/u8:20/6638:
 #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
 #1: ffffc90019a0fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
 #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by syz.0.258/7337:
3 locks held by syz-executor/9806:
 #0: ffffffff8ea6aba8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ea6aba8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8ea6aba8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
 #2: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #2: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.6.723/9814:
1 lock held by syz.1.718/9820:
 #0: ffffffff8df43300 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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]
 __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:346 [inline]
 watchdog+0xfb5/0x1000 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9814 Comm: syz.6.723 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4317 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x116/0x2a0 kernel/locking/lockdep.c:4410
Code: 48 63 83 28 0b 00 00 49 83 c4 28 49 39 c7 7d 44 49 83 ff 31 73 2d 41 8b 44 24 20 a9 00 00 04 00 74 db 25 00 00 03 00 83 f8 01 <ba> 03 00 00 00 83 da 00 48 89 df 4c 89 e6 e8 07 46 00 00 85 c0 75
RSP: 0018:ffffc9000458f8a0 EFLAGS: 00000097
RAX: 0000000000000000 RBX: ffff88802bd19e80 RCX: 944a992c84ddd400
RDX: 0000000000000000 RSI: ffffffff8d7a3ef2 RDI: ffffffff8bbf81e0
RBP: ffffc9000458fa10 R08: ffffffff8f7deb77 R09: 1ffffffff1efbd6e
R10: dffffc0000000000 R11: fffffbfff1efbd6f R12: ffff88802bd1a9b0
R13: 1ffff920008b1f2c R14: ffff88802bd1a9b0 R15: 0000000000000000
FS:  00007f11ee9bc6c0(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 0000000032cdc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
 __call_rcu_common kernel/rcu/tree.c:3148 [inline]
 call_rcu+0x6ff/0x9c0 kernel/rcu/tree.c:3243
 destroy_inode fs/inode.c:401 [inline]
 evict+0x931/0xae0 fs/inode.c:861
 __dentry_kill+0x209/0x660 fs/dcache.c:670
 shrink_kill+0xa9/0x2c0 fs/dcache.c:1137
 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164
 shrink_dcache_sb+0x218/0x3a0 fs/dcache.c:1285
 reconfigure_super+0x502/0x890 fs/super.c:1055
 do_remount fs/namespace.c:3286 [inline]
 path_mount+0xd29/0xff0 fs/namespace.c:4036
 do_mount fs/namespace.c:4057 [inline]
 __do_sys_mount fs/namespace.c:4246 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4223
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11edb8f749
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:00007f11ee9bc038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f11edde5fa0 RCX: 00007f11edb8f749
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000
RBP: 00007f11edc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000140070 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11edde6038 R14: 00007f11edde5fa0 R15: 00007ffd38f0d0d8
 </TASK>