INFO: task kworker/u4:10:4344 blocked for more than 143 seconds.
Not tainted 5.15.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:10 state:D stack:22656 pid: 4344 ppid: 2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:102
jfs_write_inode+0x141/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1495 [inline]
__writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1705
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2001
wb_writeback+0x455/0xb90 fs/fs-writeback.c:2106
wb_check_background_flush fs/fs-writeback.c:2172 [inline]
wb_do_writeback fs/fs-writeback.c:2260 [inline]
wb_workfn+0xb47/0xe60 fs/fs-writeback.c:2288
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11bea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3934:
#0: ffff88814c8d1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026362e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
5 locks held by kworker/1:5/4214:
#0: ffff88801b874d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000315fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff888147c31220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#2: ffff888147c31220 (&dev->mutex){....}-{3:3}, at: hub_event+0x18f/0x4fa0 drivers/usb/core/hub.c:5781
#3: ffff888020050220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#3: ffff888020050220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
#4: ffff8880200531a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#4: ffff8880200531a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
4 locks held by kworker/u4:10/4344:
#0: ffff888142180938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000326fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88805c16a0e0 (&type->s_umount_key#65){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
#3: ffff88805ed86788 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1c7/0x520 fs/jfs/inode.c:102
4 locks held by syz.3.239/5107:
4 locks held by udevd/6676:
#0: ffff888058700540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
#1: ffff88805f605c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112
#2: ffff88807f1161d8 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113
#3: ffff8880200531a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#3: ffff8880200531a8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4267 Comm: kworker/u4:7 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: 0x0 (phy10)
RIP: 0010:this_cpu_pvti arch/x86/include/asm/kvmclock.h:13 [inline]
RIP: 0010:kvm_clock_read arch/x86/kernel/kvmclock.c:79 [inline]
RIP: 0010:kvm_sched_clock_read+0x7/0x40 arch/x86/kernel/kvmclock.c:91
Code: 48 89 da 48 c7 c1 20 68 08 8a 5b e9 e3 97 62 08 89 cf 48 89 de 31 d2 e8 e7 83 c7 02 eb d4 0f 1f 44 00 00 65 ff 05 91 58 ce 7e <65> 48 8b 3d 11 5d ce 7e e8 bc 05 00 00 65 ff 0d 7d 58 ce 7e 74 08
RSP: 0018:ffffc90002f4fae0 EFLAGS: 00000086
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff89a927ff
RDX: 0000000000000001 RSI: ffff888025b88000 RDI: 0000000000000000
RBP: ffffc90002f4fd88 R08: dffffc0000000000 R09: ffffed1003b2db29
R10: ffffed1003b2db29 R11: 1ffff11003b2db28 R12: ffff88801d96d988
R13: 1ffff11003b2db31 R14: ffff888025b88000 R15: ffff88801d96d940
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f037a1c5178 CR3: 000000007d13f000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
sched_clock_cpu+0x15/0x3c0 kernel/sched/clock.c:371
cpu_clock include/linux/sched/clock.h:79 [inline]
psi_task_switch+0x49/0x810 kernel/sched/psi.c:835
psi_sched_switch kernel/sched/stats.h:148 [inline]
__schedule+0x1cef/0x43b0 kernel/sched/core.c:6371
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
worker_thread+0xf5c/0x12a0 kernel/workqueue.c:2478
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287