INFO: task kworker/u8:6:1131 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:20224 pid:1131 tgid:1131 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
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+0x7e1/0x1240 fs/fs-writeback.c:1802
writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 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+0xad2/0xed0 fs/fs-writeback.c:2403
process_one_work+0x93a/0x15a0 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
Showing all locks held in the system:
4 locks held by kworker/u8:1/13:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90000127b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff8880782800e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff8880742e81c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by khungtaskd/31:
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u9:0/52:
#0: ffff88801e79a148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90000bd7b80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88807bfa4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
4 locks held by kworker/u8:6/1131:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000419fb80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff888032da40e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888059d42f90 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:8/2023:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90004f27b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff888035b3e0e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888059d46fa8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:9/2219:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90005067b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88803503a0e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff8880742f6fa8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:10/3463:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000bba7b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88805e15e0e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888059c8b8b8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:13/4100:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000ca07b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88807b1100e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff8880742f2f90 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:14/4582:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000d7a7b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88805a7b40e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888059f838b8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5585:
#0: ffff8880311590a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
5 locks held by syz.0.17/6015:
5 locks held by syz.1.18/6037:
5 locks held by syz.2.19/6059:
5 locks held by syz.3.20/6088:
5 locks held by syz.4.21/6118:
5 locks held by syz.5.22/6151:
4 locks held by kworker/u8:22/6154:
#0: ffff8881416b1948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90003b17b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88805dc320e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff8880112081c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
5 locks held by syz.6.23/6193:
3 locks held by kworker/u8:25/6196:
#0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90003dffb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
5 locks held by syz.7.24/6230:
5 locks held by syz.8.25/6263:
3 locks held by syz-executor/6274:
#0: ffffffff8ea937a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ea937a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8ea937a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
#2: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
=============================================
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 10/25/2025
Call Trace:
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+0xf95/0xfe0 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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6193 Comm: syz.6.23 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:dtSplitRoot+0x775/0x16c0 fs/jfs/jfs_dtree.c:1979
Code: 48 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 4f 0e 00 00 44 88 75 00 49 0f be ee 40 0f b6 f5 bf ff 00 00 00 e8 2b 73 77 fe <40> 84 ed 78 33 e8 21 70 77 fe 48 c1 e5 05 4c 01 ed 49 89 ed 49 c1
RSP: 0018:ffffc90003d8f488 EFLAGS: 00000293
RAX: ffffffff834a4365 RBX: 0000000000000004 RCX: 0000000000000000
RDX: ffff88802b9d1e80 RSI: 0000000000000000 RDI: 00000000000000ff
RBP: 0000000000000000 R08: 0000000200000000 R09: 0000000000000000
R10: 00300065006c0069 R11: 006605ff00000020 R12: dffffc0000000000
R13: ffff888076621000 R14: 0000000000000000 R15: 1ffff1100ecc4202
FS: 00005555750bc500(0000) GS:ffff888125f37000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd81164888 CR3: 00000000764c4000 CR4: 00000000003526f0
Call Trace:
dtSplitUp fs/jfs/jfs_dtree.c:993 [inline]
dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871
jfs_rename+0x7bc/0x1610 fs/jfs/namei.c:1225
vfs_rename+0xbb6/0xee0 fs/namei.c:5929
do_renameat2+0x538/0x8e0 fs/namei.c:6047
__do_sys_rename fs/namei.c:6090 [inline]
__se_sys_rename fs/namei.c:6088 [inline]
__x64_sys_rename+0x82/0x90 fs/namei.c:6088
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdafc38f749
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:00007ffe096b0248 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007fdafc5e5fa0 RCX: 00007fdafc38f749
RDX: 0000000000000000 RSI: 0000200000000640 RDI: 00002000000000c0
RBP: 00007fdafc413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdafc5e5fa0 R14: 00007fdafc5e5fa0 R15: 0000000000000002