INFO: task syz.0.919:9032 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.0.919 state:D stack:26360 pid:9032 tgid:9031 ppid:5616 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7579
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1666
__rt_mutex_slowlock kernel/locking/rtmutex.c:1743 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1783 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1823
__rt_mutex_lock kernel/locking/rtmutex.c:1838 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
sync_bdevs+0x27e/0x470 block/bdev.c:1297
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3ad2cce59
RSP: 002b:00007fb3ab526028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fb3ad545fa0 RCX: 00007fb3ad2cce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb3ad545fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3ad546038 R14: 00007fb3ad545fa0 R15: 00007fff3c027438
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
2 locks held by getty/5366:
#0: ffff888036d330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:8/5781:
#0: ffff88801af53138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc900056f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffff88802a9ce210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#2: ffff88802a9ce210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899
#3: ffff888076126210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#3: ffff888076126210 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
3 locks held by kworker/u8:25/6724:
#0: ffff88802ba12938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc900063e7c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffff88802e0a21b8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xe8/0x1020 net/batman-adv/bat_iv_ogm.c:903
1 lock held by udevd/7862:
#0: ffff8880274d24c8 (&disk->open_mutex#5){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:948
4 locks held by udevd/7864:
#0: ffff888027af6838 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb8/0xe20 fs/seq_file.c:183
#1: ffff888036ded478 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff888068342f08 (kn->active#34){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888068342f08 (kn->active#34){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888076126210 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1107 [inline]
#3: ffff888076126210 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143
1 lock held by syz.0.919/9032:
#0: ffff8880274d24c8 (&disk->open_mutex#5){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1297
1 lock held by syz.1.1037/9491:
#0: ffff8880274d24c8 (&disk->open_mutex#5){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1297
2 locks held by syz.2.1192/10186:
#0: ffff888040af00d0 (&type->s_umount_key#94/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
#1: ffff8880274d24c8 (&disk->open_mutex#5){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:948
2 locks held by kworker/u8:42/10731:
#0: ffff88813fe54138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc900077efc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
2 locks held by kworker/u8:48/10737:
#0: ffff88813fe54138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000695fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
5 locks held by syz.6.1455/11232:
#0: ffffffff8e059d50 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
#1: ffffffff8e29f878 (jump_label_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#1: ffffffff8e29f878 (jump_label_mutex){+.+.}-{4:4}, at: static_key_slow_inc_cpuslocked+0x39/0xf0 kernel/jump_label.c:165
#2: ffffffff8e070458 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
#3: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8e1cac60 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#4: ffff88813fe4cc58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#4: ffff88813fe4cc58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: ktimers/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4856 [inline]
RIP: 0010:__lock_acquire+0x35e/0x2d10 kernel/locking/lockdep.c:5189
Code: 09 d4 41 09 cc 41 09 dc 45 89 64 c7 20 41 89 7c c7 24 4c 89 7c 24 20 4d 8d 2c c7 41 81 e4 ff 1f 00 00 4c 0f a3 25 12 dc 00 12 <73> 15 49 69 c4 c8 00 00 00 48 8d 80 d0 e4 42 93 4c 8b 74 24 08 eb
RSP: 0018:ffffc90000a4fa20 EFLAGS: 00000007
RAX: 0000000000000019 RBX: 0000000000060000 RCX: 000000000000007d
RDX: 0000000000080000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000005 R08: ffffffff81b2f43d R09: ffffffff99a9b708
R10: dffffc0000000000 R11: fffff52000149f80 R12: 000000000000007d
R13: ffff88801e2dabc8 R14: ffff88801e2d9f00 R15: ffff88801e2dab00
FS: 0000000000000000(0000) GS:ffff888125d7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c410a34 CR3: 000000001df84000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870
seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73
ktime_get_update_offsets_now+0x5d/0x3e0 kernel/time/timekeeping.c:2725
hrtimer_update_base kernel/time/hrtimer.c:683 [inline]
hrtimer_run_softirq+0xba/0x260 kernel/time/hrtimer.c:2112
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1155
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245