INFO: task kworker/u4:4:58 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4 state:D stack:20328 pid:58 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
INFO: task syz.0.130:6712 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.130 state:D stack:25576 pid:6712 ppid:5770 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
__lock_metapage fs/jfs/jfs_metapage.c:50 [inline]
lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64
__get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639
ea_write+0x5e3/0xdd0 fs/jfs/xattr.c:256
ea_put fs/jfs/xattr.c:626 [inline]
__jfs_setxattr+0x931/0x1150 fs/jfs/xattr.c:792
__jfs_xattr_set+0xdb/0x170 fs/jfs/xattr.c:941
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3a8dd8f749
RSP: 002b:00007f3a8ebd4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f3a8dfe6090 RCX: 00007f3a8dd8f749
RDX: 0000200000000640 RSI: 0000200000000600 RDI: 00002000000005c0
RBP: 00007f3a8de13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a8dfe6128 R14: 00007f3a8dfe6090 R15: 00007ffca6066178
Showing all locks held in the system:
2 locks held by kworker/0:0/8:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900000d7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900000d7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by khungtaskd/28:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:4/58:
#0: ffff888019e7c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888019e7c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90001597d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90001597d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807de360e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff8880580d70c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
2 locks held by kworker/u4:8/1114:
4 locks held by kworker/u4:9/1129:
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004abfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004abfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
#3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by kworker/u4:10/2940:
5 locks held by kworker/u4:12/3472:
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000cdd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000cdd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
#3: ffff88805840e250 (&devlink->lock_key#10){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:60 [inline]
#3: ffff88805840e250 (&devlink->lock_key#10){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xe1/0x340 net/devlink/core.c:285
#4: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:335 [inline]
#4: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x384/0x4a0 drivers/net/netdevsim/netdev.c:401
1 lock held by dhcpcd/5435:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
2 locks held by getty/5527:
#0: ffff88814c9670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by kworker/0:3/5814:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900047efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900047efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
4 locks held by syz.0.130/6712:
#0: ffff88807de36418 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff8880580d7490 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff8880580d7490 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x145/0x2f0 fs/xattr.c:321
#2: ffff8880580d70c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: __jfs_xattr_set+0xba/0x170 fs/jfs/xattr.c:940
#3: ffff8880580d7160 (&jfs_ip->xattr_sem){++++}-{3:3}, at: __jfs_setxattr+0xe2/0x1150 fs/jfs/xattr.c:678
3 locks held by syz-executor/8565:
#0: ffff8880785d8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff8880785d8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709
#1: ffff8880785d80b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
1 lock held by syz-executor/8650:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
4 locks held by syz.3.389/8715:
#0: ffff88807c9b4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff88807c9b4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709
#1: ffff88807c9b40b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
#3: ffff88802cf42338 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1763
3 locks held by syz.8.392/8724:
#0: ffff88802c4a0e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff88802c4a0e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709
#1: ffff88802c4a00b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2940 Comm: kworker/u4:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: iou_exit io_ring_exit_work
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xe3/0x760 kernel/locking/lockdep.c:4340
Code: 00 48 c7 c0 80 b4 e9 96 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 0b 05 00 00 83 3d 08 f2 82 15 00 75 6c 48 c7 44 24 40 00 00 00 00 <9c> 8f 44 24 40 f6 44 24 41 02 0f 85 87 03 00 00 48 c7 c0 80 b4 e9
RSP: 0018:ffffc9000c0b76e0 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff92001816ee0 RCX: ffffffff96e9b403
RDX: dffffc0000000000 RSI: ffffffff8afc6f60 RDI: ffffffff8afc6f20
RBP: ffffc9000c0b7788 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: dffffc0000000000
R13: ffff88806a97e2c0 R14: ffffffff970a6228 R15: 1ffff92001816ef4
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4662a3 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x86/0x110 kernel/locking/spinlock.c:194
__debug_check_no_obj_freed lib/debugobjects.c:999 [inline]
debug_check_no_obj_freed+0x51f/0x540 lib/debugobjects.c:1020
slab_free_hook mm/slub.c:1786 [inline]
slab_free_freelist_hook+0xd2/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
io_cqring_overflow_kill+0x37f/0x410 io_uring/io_uring.c:667
io_ring_exit_work+0x195/0x7e0 io_uring/io_uring.c:3190
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293