INFO: task syz.3.706:8692 blocked for more than 143 seconds.
Not tainted 6.16.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.706 state:D stack:26104 pid:8692 tgid:8691 ppid:5839 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
device_lock include/linux/device.h:884 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
do_dentry_open+0xdf0/0x1970 fs/open.c:964
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:3896 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4055
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f924918d550
RSP: 002b:00007f924a05eb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000301 RCX: 00007f924918d550
RDX: 0000000000000301 RSI: 00007f924a05ec10 RDI: 00000000ffffff9c
RBP: 00007f924a05ec10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f92493b6038 R14: 00007f92493b5fa0 R15: 00007fff306772a8
Showing all locks held in the system:
4 locks held by rcu_exp_gp_kthr/18:
#0: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
#1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff888026bde428 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
#2: ffff888026bde428 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x6e/0x1290 kernel/sched/core.c:4227
#3: ffff8880b8739e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5597:
#0: ffff88814c59a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by kworker/0:8/5989:
#0: ffff8880216ef548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880216ef548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90005397bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90005397bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffff8881443ba198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff8881443ba198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88805634f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff88805634f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
#4: ffff88802625d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#4: ffff88802625d160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
#5: ffffffff8dfe4850 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
4 locks held by udevd/6004:
#0: ffff888071d98d58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff888059024488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154
#2: ffff8880342865a8 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155
#3: ffff88805634f198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:889 [inline]
#3: ffff88805634f198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.3.706/8692:
#0: ffff8881443ba198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#0: ffff8881443ba198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by sed/10687:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 10687 Comm: sed Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x1/0x120 lib/smp_processor_id.c:13
Code: e0 b9 e1 8b 48 c7 c6 20 ba e1 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 05 ee ed 35 07 48 89 44 24 08
RSP: 0018:ffffc900033974c0 EFLAGS: 00000287
RAX: 0000000000000000 RBX: ffffffff822b406a RCX: ffff88802614bc00
RDX: 0000000000000000 RSI: ffffffff8be1ba20 RDI: ffffffff8be1b9e0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822b406a
R10: dffffc0000000000 R11: fffff940009ff581 R12: dffffc0000000000
R13: ffffffff822b406a R14: ffffffff8e13f1a0 R15: ffff88813fffb060
FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf86c5b6b0 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:745
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5882
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock_sched include/linux/rcupdate.h:953 [inline]
pfn_valid+0x3b2/0x490 include/linux/mmzone.h:2168
page_table_check_clear+0x21/0x700 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:714 [inline]
zap_present_folio_ptes mm/memory.c:1505 [inline]
zap_present_ptes mm/memory.c:1590 [inline]
do_zap_pte_range mm/memory.c:1691 [inline]
zap_pte_range mm/memory.c:1735 [inline]
zap_pmd_range mm/memory.c:1827 [inline]
zap_pud_range mm/memory.c:1856 [inline]
zap_p4d_range mm/memory.c:1877 [inline]
unmap_page_range+0x3249/0x41c0 mm/memory.c:1898
unmap_single_vma mm/memory.c:1941 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1985
exit_mmap+0x248/0xb50 mm/mmap.c:1284
__mmput+0x118/0x410 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x22e0 kernel/exit.c:952
do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
__do_sys_exit_group kernel/exit.c:1116 [inline]
__se_sys_exit_group kernel/exit.c:1114 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf86c5b6c5
Code: Unable to access opcode bytes at 0x7fdf86c5b69b.
RSP: 002b:00007fff2dcd4108 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fdf86d5cfe8 RCX: 00007fdf86c5b6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdf86d5b680 R15: 00007fdf86d5d000