INFO: task syz.3.5004:20817 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.5004 state:D stack:28728 pid:20817 tgid:20816 ppid:14084 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
rwsem_down_read_slowpath+0x5af/0xb40 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0xed/0x4c0 kernel/locking/rwsem.c:1576
__super_lock fs/super.c:62 [inline]
super_lock+0x326/0x3f0 fs/super.c:124
__iterate_supers+0x38b/0x4a0 fs/super.c:994
ksys_sync+0x87/0xf0 fs/sync.c:102
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f963279e159
RSP: 002b:00007f9633738028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f9632a25fa0 RCX: 00007f963279e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f9632a25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9632a26038 R14: 00007f9632a25fa0 R15: 00007fffa4160bf8
Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#0:
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837
locks held by kworker/u8:4/78: 3, on CPU#0:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc900024dfd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffffffff90ccf7c0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
locks held by kworker/u8:11/1524: 2, last CPU#1:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90005f87d08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by kworker/0:3/2341: 6, on CPU#0:
#0: ffff88801fed4d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000730fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802b6241d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b6241d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5912
#3: ffff88802ac1f568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3265 [inline]
#3: ffff88802ac1f568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5477 [inline]
#3: ffff88802ac1f568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#3: ffff88802ac1f568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#3: ffff88802ac1f568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2b3e/0x4420 drivers/usb/core/hub.c:5966
#4: ffff88802a1cd160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5478 [inline]
#4: ffff88802a1cd160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#4: ffff88802a1cd160 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#4: ffff88802a1cd160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2b67/0x4420 drivers/usb/core/hub.c:5966
#5: ffffffff9027e228 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a1/0x1bd0 drivers/usb/core/hub.c:3080
locks held by getty/5364: 2, on CPU#0:
#0: ffff888038bc40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor/5588: 2, last CPU#0:
#0: ffff88802da75038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff88802da75038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz.0.3333/15571: 2, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super fs/super.c:631 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:628
#1: ffffffff8f287800 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by syz.3.5004/20817: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.2.5127/21221: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.2.5127/21224: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.2.5127/21228: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.1.5132/21240: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.1.5132/21241: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.1.5132/21242: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.6.5328/22169: 1, on CPU#0:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.6.5328/22172: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.6.5328/22174: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.8.5364/22295: 1, on CPU#0:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.8.5364/22296: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.5383/22370: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.5383/22371: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.9.5383/22374: 1, on CPU#1:
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff8880338340e8 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz.0.5531/22946: 2, on CPU#1:
#0: ffffffff90ccf7c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
#0: ffffffff90ccf7c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3587
#1: ffffffff8edf7f68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
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: 22978 Comm: syz.5.5540 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0033:0x7f3563451801
Code: 39 d0 75 dc 48 89 f0 25 ff 1f 00 00 49 89 34 c1 41 88 3c 00 31 c0 c3 66 90 41 38 3c 10 74 0b 41 88 3c 10 31 c0 49 89 34 d1 c3 01 00 00 00 c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 7c
RSP: 002b:00007fffc72e1358 EFLAGS: 00000246
RAX: 0000000082691885 RBX: ffffffff82691885 RCX: ffffffff82691885
RDX: 0000000000001885 RSI: ffffffff82691885 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f3563810000 R09: 00007f3563812000
R10: 0000000082691889 R11: 0000000000000004 R12: 00007f3563826038
R13: 0000000000068e19 R14: ffffffff826914d1 R15: 00007f3564355720
FS: 000055557527f500 GS: 0000000000000000