INFO: task syz.2.2733:16752 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2733 state:D stack:24808 pid:16752 ppid:15095 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
sync_bdevs+0x1af/0x330 block/bdev.c:1076
ksys_sync+0xc6/0x170 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f558559c819
RSP: 002b:00007f55864b2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f5585816180 RCX: 00007f558559c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f5585816180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5585816218 R14: 00007f5585816180 R15: 00007ffff9f25ae8
Showing all locks held in the system:
1 lock held by kworker/u4:1/12:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
1 lock held by rcu_preempt/17:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
1 lock held by khungtaskd/28:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:6/1005:
2 locks held by getty/5530:
#0: ffff88814cbbb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
5 locks held by kworker/1:0/10738:
#0: ffff88814267b538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88814267b538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90018817d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90018817d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffff88814370e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff88814370e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff888025529508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3215 [inline]
#3: ffff888025529508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5426 [inline]
#3: ffff888025529508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
#3: ffff888025529508 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5833 [inline]
#3: ffff888025529508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x21d0/0x49f0 drivers/usb/core/hub.c:5915
#4: ffff88802555a368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5427 [inline]
#4: ffff88802555a368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
#4: ffff88802555a368 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5833 [inline]
#4: ffff88802555a368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x21f8/0x49f0 drivers/usb/core/hub.c:5915
1 lock held by udevd/13074:
#0: ffff8880222a14c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/13095:
#0: ffff8880225924c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/13865:
#0: ffff8880222c34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/13868:
#0: ffff88802221f4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/14265:
#0: ffff888141b084c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz.2.2733/16752:
#0: ffff8880222a14c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1076
7 locks held by kworker/1:2H/17425:
1 lock held by udevd/17741:
#0: ffff88802278a4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/17746:
#0: ffff8880226bd4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz.1.3046/17898:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17425 Comm: kworker/1:2H Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:__lock_acquire+0xcc/0x7d40 kernel/locking/lockdep.c:5002
Code: 10 48 89 8c 24 d0 00 00 00 42 c7 44 01 18 f3 f3 f3 f3 65 48 8b 1d 74 85 9b 7e 48 c7 c0 ac 4a 8b 8e 48 c1 e8 03 42 0f b6 04 00 <84> c0 48 89 bc 24 88 00 00 00 0f 85 88 67 00 00 83 3d 39 1a 23 0d
RSP: 0018:ffffc900001f0620 EFLAGS: 00000807
RAX: 0000000000000000 RBX: ffff88802dc05a00 RCX: 1ffff9200003e0e8
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff97545838
RBP: ffffc900001f0868 R08: dffffc0000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1d162be R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000188030 CR3: 000000004b70e000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
debug_object_assert_init+0x9c/0x2f0 lib/debugobjects.c:898
debug_timer_assert_init kernel/time/timer.c:792 [inline]
debug_assert_init kernel/time/timer.c:837 [inline]
__mod_timer+0x55/0xdb0 kernel/time/timer.c:1020
mrp_periodic_timer_arm net/802/mrp.c:617 [inline]
mrp_periodic_timer+0x1c9/0x210 net/802/mrp.c:629
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2008 [inline]
RIP: 0010:vprintk_emit+0x46f/0x610 kernel/printk/printk.c:2340
Code: 85 3f 01 00 00 e8 c1 a9 1b 00 45 89 f7 48 85 db 48 8b 1c 24 75 07 e8 b0 a9 1b 00 eb 06 e8 a9 a9 1b 00 fb 48 c7 c7 00 64 12 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 b1
RSP: 0018:ffffc90003437460 EFLAGS: 00000293
RAX: ffffffff816b7857 RBX: ffffffff816b76fb RCX: ffff88802dc05a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8d126400
RBP: ffffc90003437550 R08: ffffffff911c555f R09: 1ffffffff2238aab
R10: dffffc0000000000 R11: fffffbfff2238aac R12: dffffc0000000000
R13: 1ffff92000686e90 R14: 000000000000003f R15: 000000000000003f
_printk+0xde/0x130 kernel/printk/printk.c:2366
buffer_io_error fs/buffer.c:130 [inline]
end_buffer_async_read+0x45d/0x660 fs/buffer.c:260
end_bio_bh_io_sync+0xb7/0x110 fs/buffer.c:2784
req_bio_endio block/blk-mq.c:786 [inline]
blk_update_request+0x597/0xe40 block/blk-mq.c:931
blk_mq_end_request block/blk-mq.c:1058 [inline]
blk_mq_dispatch_rq_list+0xf10/0x1ea0 block/blk-mq.c:2105
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
__blk_mq_sched_dispatch_requests+0xec8/0x16e0 block/blk-mq-sched.c:309
blk_mq_sched_dispatch_requests+0xfb/0x1b0 block/blk-mq-sched.c:333
blk_mq_run_work_fn+0x169/0x2f0 block/blk-mq.c:2506
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293