INFO: task kworker/u8:8:5935 blocked for more than 143 seconds.
Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:23232 pid:5935 tgid:5935 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound netfs_write_collection_worker
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0xf43/0x5890 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6857
bit_wait+0x15/0xe0 kernel/sched/wait_bit.c:237
__wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64
wait_on_bit include/linux/wait_bit.h:77 [inline]
netfs_retry_writes+0x2fa/0x1a00 fs/netfs/write_retry.c:217
netfs_collect_write_results fs/netfs/write_collect.c:352 [inline]
netfs_write_collection_worker+0x23de/0x37c0 fs/netfs/write_collect.c:374
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Showing all locks held in the system:
2 locks held by kworker/0:0/8:
1 lock held by khungtaskd/30:
#0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1bccc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
1 lock held by klogd/5181:
#0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline]
#0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591
2 locks held by getty/5575:
#0: ffff88814e1a50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
6 locks held by kworker/1:4/5827:
#0: ffff888020ec1148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc90002ef7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
#2: ffff888145b1d190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#2: ffff888145b1d190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5861
#3: ffff8880255e1190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#3: ffff8880255e1190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#4: ffff8880384e6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#4: ffff8880384e6160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#5: ffff8880594f5c18 (&dev->ctrl_urb_lock){+.+.}-{4:4}, at: em28xx_write_regs_req+0x14c/0x410 drivers/media/usb/em28xx/em28xx-core.c:147
2 locks held by kworker/u8:8/5935:
#0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc9000452fd18 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
2 locks held by kworker/u8:10/5967:
#0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc900045dfd18 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
4 locks held by udevd/11470:
#0: ffff888059641668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182
#1: ffff88803415bc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff8880472053c8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff8880255e1190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#3: ffff8880255e1190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729
3 locks held by syz.8.1141/11669:
#0: ffff88804b9dc420 (sb_writers#19){.+.+}-{0:0}, at: do_pwritev+0x1b1/0x270 fs/read_write.c:1146
#1: ffff888077ed27e8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: netfs_start_io_write+0x59/0x80 fs/netfs/locking.c:112
#2: ffff888077ed2ba0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_begin_writethrough+0x64/0x1c0 fs/netfs/write_issue.c:624
3 locks held by syz.7.1157/11751:
#0: ffff88803f072420 (sb_writers#19){.+.+}-{0:0}, at: do_pwritev+0x1b1/0x270 fs/read_write.c:1146
#1: ffff888077f44e88 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: netfs_start_io_write+0x59/0x80 fs/netfs/locking.c:112
#2: ffff888077f45240 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_begin_writethrough+0x64/0x1c0 fs/netfs/write_issue.c:624
1 lock held by syz-executor/11988:
#0: ffffffff8e1c8138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334
1 lock held by syz.5.1573/13823:
#0: ffff888012765c08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
#0: ffff888012765c08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111