INFO: task syz.5.1756:12374 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.5.1756 state:D stack:28120 pid:12374 tgid:12371 ppid:9176 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
bdev_open+0xa2/0xe40 block/bdev.c:962
bdev_file_open_by_dev block/bdev.c:1076 [inline]
bdev_file_open_by_dev+0x179/0x210 block/bdev.c:1051
setup_bdev_super+0x385/0x730 fs/super.c:1609
get_tree_bdev_flags+0x363/0x620 fs/super.c:1689
vfs_get_tree+0x92/0x320 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount fs/namespace.c:3712 [inline]
path_mount+0x7d0/0x23c0 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcde7f9aeb9
RSP: 002b:00007fcde8e17028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fcde8216090 RCX: 00007fcde7f9aeb9
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 0000200000000140
RBP: 00007fcde8008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000208800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcde8216128 R14: 00007fcde8216090 R15: 00007ffdae1872a8
Showing all locks held in the system:
6 locks held by kworker/0:0/9:
#0: ffff888142e9c948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900000e7c98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888143f88198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888143f88198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88801f757198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88801f757198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#4: ffff88802b19f160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88802b19f160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#5: ffff8881437cf168 (hcd->bandwidth_mutex){+.+.}-{4:4}, at: usb_set_interface+0x294/0xe20 drivers/usb/core/message.c:1564
1 lock held by khungtaskd/31:
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5569:
#0: ffff8880372ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:6/5948:
#0: ffff888142e9c948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90003147c98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888144330198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888144330198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888037382198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888037382198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#4: ffff8880714c8160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff8880714c8160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#5: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#5: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
1 lock held by udevd/7649:
#0: ffff8880262af358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
1 lock held by udevd/7670:
#0: ffff88802646f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
4 locks held by udevd/7975:
#0: ffff888029407e80 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:182
#1: ffff888031f77c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
#2: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: fs_reclaim_acquire+0x70/0x100 mm/page_alloc.c:4339
#3: ffffffff9af40c88 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x151/0x360 kernel/time/clockevents.c:326
8 locks held by kworker/0:1/9436:
3 locks held by kworker/u8:20/10289:
#0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1:
ffffc90003bffc98 ((work_completion)(©->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff8e5ef980 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816
2 locks held by syz.5.1756/12374:
#0: ffff8880284e40e0 (&type->s_umount_key#88/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:344
#1: ffff88802646f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:962
=============================================
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 01/13/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5948 Comm: kworker/0:6 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: events_power_efficient hub_init_func2
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4786 [inline]
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4776 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4875 [inline]
RIP: 0010:__lock_acquire+0x2b5/0x2630 kernel/locking/lockdep.c:5187
Code: 84 0f 05 00 00 0f b6 7e 21 44 31 cf 83 e7 60 74 e4 44 8d 48 01 65 8b 05 21 9a 01 12 85 c0 0f 84 d5 04 00 00 8b 85 00 0b 00 00 <85> c0 75 10 44 8b bd 18 0b 00 00 45 85 ff 0f 84 e6 0b 00 00 41 bf
RSP: 0018:ffffc90000007be0 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff888032fbd550 RCX: 0000000000000004
RDX: 0000000000000002 RSI: ffff888032fbd500 RDI: 0000000000000040
RBP: ffff888032fbc980 R08: 0000000000000001 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000040 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881245db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4531cb CR3: 0000000075188000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825
_raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
raw_spin_rq_lock kernel/sched/sched.h:1580 [inline]
rq_lock kernel/sched/sched.h:1907 [inline]
ttwu_queue kernel/sched/core.c:3892 [inline]
try_to_wake_up+0xb60/0x1a60 kernel/sched/core.c:4218
hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:2013
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x109/0x3c0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline]
RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2425
Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 28 21 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 f6 1b 21 00 48 85 ed 0f 85 27 01 00 00 08 21 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc90003147708 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 000000000000001d RCX: ffffffff81e5db6a
RDX: ffff888032fbc980 RSI: ffffffff81e5db74 RDI: ffff888032fbc980
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000075a9 R12: 1ffff92000628ee3
R13: 0000000000000200 R14: ffff88801eeb4980 R15: ffffc900031478d0
dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4914
dev_printk_emit+0xd2/0x10d drivers/base/core.c:4925
__dev_printk+0xcb/0x100 drivers/base/core.c:4937
_dev_err+0xef/0x127 drivers/base/core.c:4980
hub_activate.cold+0x35/0xef drivers/usb/core/hub.c:1334
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246