INFO: task kworker/u8:9:3536 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:22552 pid:3536 tgid:3536 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
f2fs_balance_fs+0x513/0x780 fs/f2fs/segment.c:454
f2fs_write_inode+0x49d/0x870 fs/f2fs/inode.c:812
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_start_all fs/fs-writeback.c:2284 [inline]
wb_do_writeback fs/fs-writeback.c:2310 [inline]
wb_workfn+0x90b/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.0.52:6220 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.52 state:D stack:25272 pid:6220 tgid:6219 ppid:5817 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833
iterate_supers+0xb8/0x180 fs/super.c:934
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f187f58e969
RSP: 002b:00007f1880494038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f187f7b5fa0 RCX: 00007f187f58e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f187f7b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f187f7b5fa0 R15: 00007fffc5e9e388
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by kworker/u8:3/53:
#0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
3 locks held by kworker/u8:4/66:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000156fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000156fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by kworker/u8:9/3536:
#0: ffff888143ad9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888143ad9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000b00fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000b00fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff88807b1653b0 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
#3: ffff88807b1653b0 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x513/0x780 fs/f2fs/segment.c:454
1 lock held by dhcpcd/5486:
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121
2 locks held by getty/5581:
#0: ffff888030a950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036242f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:6/5913:
#0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000a7f7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000a7f7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#2: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
5 locks held by syz.1.43/6126:
2 locks held by syz.0.52/6220:
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.6.83/6623:
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.6.83/6625:
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz-executor/7869:
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
#1: ffff88802f6ccd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline]
#1: ffff88802f6ccd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#1: ffff88802f6ccd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: do_setlink+0x370/0x40d0 net/core/rtnetlink.c:3051
7 locks held by syz-executor/7939:
#0: ffff88803034c420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#0: ffff88803034c420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680
#1: ffff888044203488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325
#2: ffff888143f42788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8eb88668 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216
#4: ffff88805993f0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff88805993f0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
#4: ffff88805993f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292
#5: ffff888059969250 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
#6: ffffffff8df43880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774
2 locks held by syz.5.226/7998:
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888023e020e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880247267d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
4 locks held by syz.8.243/8147:
#0: ffff88803106cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
#0: ffff88803106cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678
#1: ffff88803106c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213
#2: ffffffff8f44e208 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2065 [inline]
#2: ffffffff8f44e208 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2534
#3: ffff888078425338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
3 locks held by udevadm/8182:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8133 Comm: syz-executor Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:233 [inline]
RIP: 0010:__lock_acquire+0xa40/0xd20 kernel/locking/lockdep.c:5232
Code: e6 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 86 02 00 00 41 8b 47 20 25 ff 1f 00 00 48 0f a3 05 f0 ea db 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 e0 36 1b 93 eb 40 83 3d 07 7a
RSP: 0018:ffffc9000a7a7438 EFLAGS: 00000003
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 00000000fe09d4ff
RDX: 00000000105209fd RSI: 000000005a44979c RDI: ffff88802f7ebc00
RBP: ffff88802f7ec6f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171ca05 R12: 0000000000004008
R13: 0ac0d5affe09d4ff R14: 0000000000004008 R15: ffff88802f7ec6f0
FS: 0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005650b2288000 CR3: 000000002fbfa000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1258 [inline]
__free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2721
vfree+0x1a6/0x330 mm/vmalloc.c:3384
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x449/0xa70 fs/file_table.c:465
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d6/0x2550 kernel/exit.c:953
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbbc7907fc
Code: Unable to access opcode bytes at 0x7fdbbc7907d2.
RSP: 002b:00007ffe77d62770 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000038 RBX: 00007fdbbd4e4620 RCX: 00007fdbbc7907fc
RDX: 0000000000000038 RSI: 00007fdbbd4e4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe77d627c4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fdbbd4e4670 R15: 0000000000000000