INFO: task syz.7.346:8249 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.346 state:D stack:28296 pid:8249 tgid:8248 ppid:6939 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
device_lock include/linux/device.h:914 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
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/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f12fc38d710
RSP: 002b:00007f12fd224b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000101341 RCX: 00007f12fc38d710
RDX: 0000000000101341 RSI: 00007f12fd224c10 RDI: 00000000ffffff9c
RBP: 00007f12fd224c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f12fc5e6038 R14: 00007f12fc5e5fa0 R15: 00007ffed55d3238
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:8/2988:
2 locks held by getty/5620:
#0: ffff88814de9d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5880:
#0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
6 locks held by kworker/1:5/5947:
#0: ffff888144292d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888144292d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000531fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000531fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88807a264198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88807a264198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff888052ccb160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff888052ccb160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#5: ffffffff8e1e2750 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
4 locks held by udevd/6291:
#0: ffff88802f53b2f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182
#1: ffff8880565c5888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff88807371b1e8 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88807371b1e8 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff88807a264198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline]
#3: ffff88807a264198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz-executor/7795:
1 lock held by syz.7.346/8249:
#0: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.2.505/9383:
#0: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff88802884c198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 10793 Comm: syz.3.719 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
Code: 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e8 e0 02 00 00 <48> 83 c4 28 48 c7 c7 aa dc d8 8d e8 10 bf e1 09 b8 ff ff ff ff 65
RSP: 0000:ffffc9000bccfa90 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 9da8cb4428afcc00
RDX: 0000000000000000 RSI: ffff8880300c29c0 RDI: ffff8880300c1e40
RBP: ffffffff821227ee R08: 0000000000000000 R09: ffffffff821227ee
R10: ffffc9000bccfcec R11: fffff52001799fa6 R12: 0000000000000000
R13: ffff88807d9f0978 R14: 0000000000000001 R15: 0000000000000246
FS: 00007f306366e6c0(0000) GS:ffff8881259fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f30593da000 CR3: 000000002ec82000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401
pte_offset_map_lock include/linux/mm.h:3128 [inline]
do_anonymous_page mm/memory.c:5158 [inline]
do_pte_missing mm/memory.c:4359 [inline]
handle_pte_fault mm/memory.c:6177 [inline]
__handle_mm_fault+0x22f9/0x5400 mm/memory.c:6318
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f3062650ca6
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f306366d4a0 EFLAGS: 00010206
RAX: 0000000000fda001 RBX: 00007f306366d540 RCX: 00000000000000d2
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f306366d5e0
RBP: 0000000000000102 R08: 00007f3058400000 R09: 0000000000fda000
R10: 0000000000000000 R11: 00007f306366d550 R12: 0000000000000001
R13: 00007f306282db80 R14: 0000000000000000 R15: 00007f306366d5e0