INFO: task kworker/u4:18:4557 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:18 state:D stack:20368 pid:4557 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:108
jfs_write_inode+0x141/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1470 [inline]
__writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687
writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984
wb_writeback+0x494/0xd50 fs/fs-writeback.c:2089
wb_check_old_data_flush fs/fs-writeback.c:2189 [inline]
wb_do_writeback fs/fs-writeback.c:2242 [inline]
wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2270
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e7f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2f010 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
4 locks held by kworker/u4:18/4557:
#0: ffff88801ce68938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004cafd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffff8880553fc0e0 (&type->s_umount_key#114){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
#3: ffff8880404cde48 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:108
4 locks held by syz.2.1318/10333:
2 locks held by getty/11587:
#0: ffff88814d745098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900052b32f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
1 lock held by syz.5.1737/11992:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10333 Comm: syz.2.1318 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4748 [inline]
RIP: 0010:__lock_acquire+0x99c/0x7d10 kernel/locking/lockdep.c:4999
Code: b6 04 00 84 c0 0f 85 5e 01 00 00 83 3d 0c 12 5c 15 00 74 67 45 31 f6 49 81 c6 b8 00 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 00 <84> c0 0f 85 e6 00 00 00 41 0f b6 06 84 c0 74 0e 41 0f b6 cd 44 0f
RSP: 0018:ffffc9000d6af000 EFLAGS: 00000806
RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffffffff81644eea
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90aff3e8
RBP: ffffc9000d6af250 R08: dffffc0000000000 R09: 1ffffffff215fe7d
R10: dffffc0000000000 R11: fffffbfff215fe7e R12: ffff8880635d0b50
R13: 0000000000000003 R14: ffffffff90528eb8 R15: ffff8880635d0b50
FS: 00007fab011c46c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b41dea540 CR3: 000000007cfd5000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
finish_lock_switch kernel/sched/core.c:5002 [inline]
finish_task_switch+0x19f/0x8f0 kernel/sched/core.c:5122
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x11d9/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:dtSplitRoot+0x712/0x14e0 fs/jfs/jfs_dtree.c:1981
Code: 34 24 4d 89 f4 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 10 41 0f b6 2e 40 84 ed 78 1b e8 ce 88 90 fe ca 44 89 f1 80 e1 07 38 c1 7c e6 4c 89 f7 e8 3a 90 e1 fe eb dc
RSP: 0018:ffffc9000d6af728 EFLAGS: 00000246
RAX: ffffffff82f1f2d2 RBX: 0000000000000004 RCX: 0000000000080000
RDX: ffffc90010f33000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000000 R08: ffff88805333c11f R09: 1ffff1100a667823
R10: dffffc0000000000 R11: ffffed100a667824 R12: 1ffff1100a667800
R13: ffff8880404ce0b0 R14: ffff88805333c000 R15: 1ffff1100a667802
dtSplitUp fs/jfs/jfs_dtree.c:993 [inline]
dtInsert+0xe7b/0x5950 fs/jfs/jfs_dtree.c:871
jfs_mkdir+0x758/0xad0 fs/jfs/namei.c:270
vfs_mkdir+0x387/0x570 fs/namei.c:4114
do_mkdirat+0x1d8/0x440 fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fab0039bcc7
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fab011c3e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fab011c3ee0 RCX: 00007fab0039bcc7
RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000140 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000140 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fab011c3ea0 R14: 0000000000000000 R15: 0000000000000000