INFO: task syz.0.4594:15455 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.4594 state:D stack:27776 pid:15455 tgid:15453 ppid:5644 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
device_lock include/linux/device.h:1040 [inline]
usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80a315d60e
RSP: 002b:00007f80a411ab28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f80a411b6c0 RCX: 00007f80a315d60e
RDX: 0000000000000602 RSI: 00007f80a411ac00 RDI: ffffffffffffff9c
RBP: 00007f80a411ac00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f80a3416038 R14: 00007f80a3415fa0 R15: 00007f80a353fa48
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5383:
#0: ffff88803673f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5643:
6 locks held by kworker/1:8/5721:
3 locks held by kworker/0:12/10175:
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc90002ee7c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc90002ee7c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.0.4594/15455:
#0: ffff88802a71c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802a71c1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
1 lock held by syz.4.7055/20535:
#0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by dhcpcd/20544:
#0: ffff888025556260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#0: ffff888025556260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
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: 20408 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4868 [inline]
RIP: 0010:__lock_acquire+0x460/0x2cf0 kernel/locking/lockdep.c:5187
Code: 0f 44 ca 89 0c 24 45 8b a6 88 0b 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
RSP: 0018:ffffc90004c57150 EFLAGS: 00000046
RAX: 0000000000020007 RBX: 0000000000000004 RCX: 00000000000406eb
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801d3b49d8 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: ffffc90004c57458 R11: ffffffff81b0e840 R12: 0000000000000002
R13: 0000000000000000 R14: ffff88801d3b3d80 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888125390000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b64db5a168 CR3: 000000000e74a000 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:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 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+0x46/0x50 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:2689 [inline]
slab_free mm/slub.c:6250 [inline]
kfree+0x1c5/0x640 mm/slub.c:6565
skb_kfree_head net/core/skbuff.c:1075 [inline]
skb_free_head net/core/skbuff.c:1087 [inline]
skb_release_data+0x828/0xa60 net/core/skbuff.c:1114
skb_release_all net/core/skbuff.c:1189 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1203
netlink_broadcast_filtered+0xdab/0xeb0 net/netlink/af_netlink.c:1535
nlmsg_multicast_filtered include/net/netlink.h:1165 [inline]
nlmsg_multicast include/net/netlink.h:1184 [inline]
nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593
__neigh_notify+0x1ae/0x310 net/core/neighbour.c:3584
neigh_notify net/core/neighbour.c:3595 [inline]
neigh_cleanup_and_release+0xae/0x2b0 net/core/neighbour.c:119
neigh_periodic_work+0xb4f/0xe50 net/core/neighbour.c:1029
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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