INFO: task syz.2.1012:9908 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.2.1012 state:D stack:24872 pid:9908 tgid:9908 ppid:5646 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
request_wait_answer fs/fuse/dev.c:743 [inline]
__fuse_request_send fs/fuse/dev.c:757 [inline]
fuse_chan_send+0x1068/0x1ad0 fs/fuse/dev.c:833
fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]
fuse_flush+0x677/0x8b0 fs/fuse/file.c:504
filp_flush+0xc0/0x190 fs/open.c:1471
filp_close+0x1d/0x40 fs/open.c:1484
__range_close fs/file.c:793 [inline]
__do_sys_close_range fs/file.c:854 [inline]
__se_sys_close_range+0x3d6/0x910 fs/file.c:818
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: 0033:0x7fb51813ce59
RSP: 002b:00007ffccdb81628 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007fb5183b7da0 RCX: 00007fb51813ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fb5183b7da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007fb5183b7cb0 R11: 0000000000000246 R12: 00000000000bd3bb
R13: 00007fb5183b609c R14: 00000000000bd1bc R15: 00007fb5183b6090
Showing all locks held in the system:
1 lock held by khungtaskd/37:
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5353:
#0: ffff888032a590a0 (&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+0x460/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:10/5878:
4 locks held by kworker/1:7/5938:
6 locks held by kworker/0:8/10396:
#0: ffff8880226cad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880226cad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000631fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000631fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff888029f0c210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#2: ffff888029f0c210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899
#3: ffff888029f10658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888029f10658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888029f10658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888029f10658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888029f10658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20ad/0x4cf0 drivers/usb/core/hub.c:5953
#4: ffff888029d8db58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff888029d8db58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff888029d8db58 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff888029d8db58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20e1/0x4cf0 drivers/usb/core/hub.c:5953
#5: ffffffff8ec19120 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x17d0 drivers/usb/core/hub.c:3067
1 lock held by syz-executor/11087:
5 locks held by syz.4.1395/11761:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 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+0xfd7/0x1030 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5878 Comm: kworker/u8:10 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
Workqueue: kvfree_rcu_reclaim kfree_rcu_work
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4869 [inline]
RIP: 0010:__lock_acquire+0x450/0x2ce0 kernel/locking/lockdep.c:5187
Code: 0c 00 00 41 8d 4c 24 ff 83 f9 ff 41 bd ff ff ff ff 44 0f 4c e9 41 ff c5 41 8d 5c 24 01 49 ff cc 89 d9 83 c1 fe 78 40 45 89 e7 <41> 81 e7 ff ff ff 7f 83 f9 31 73 1d 4b 8d 0c bf 41 8b 8c ce 28 0c
RSP: 0018:ffffc90003d67238 EFLAGS: 00000013
RAX: 000000000002000b RBX: 0000000000000003 RCX: 0000000000000001
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88802f7e6980 R08: ffffffff8176d1ff R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8dfc2fc0 R12: 0000000000000001
R13: 0000000000000000 R14: ffff88802f7e5d00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126111000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555791a9a38 CR3: 0000000039ae6000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2705 [inline]
slab_free_freelist_hook mm/slub.c:2734 [inline]
slab_free_bulk mm/slub.c:6439 [inline]
kmem_cache_free_bulk+0x309/0x1260 mm/slub.c:7176
kfree_bulk include/linux/slab.h:891 [inline]
kvfree_rcu_bulk+0xc6/0x190 mm/slab_common.c:1502
kfree_rcu_work+0xe8/0x160 mm/slab_common.c:1580
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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