INFO: task syz.0.3254:18695 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.0.3254 state:D stack:28160 pid:18695 tgid:18694 ppid:17442 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
bdev_open+0xe0/0xd30 block/bdev.c:961
blkdev_open+0x470/0x610 block/fops.c:698
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f577415c84e
RSP: 002b:00007f5775081b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f57750826c0 RCX: 00007f577415c84e
RDX: 0000000000040000 RSI: 00007f5775081c00 RDI: ffffffffffffff9c
RBP: 00007f5775081c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f5774416038 R14: 00007f5774415fa0 R15: 00007ffc96014618
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5579:
#0: ffff8880365e30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/15333:
#0: ffff88802756d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz-executor/18070:
#0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.0.3254/18695:
#0: ffff88802756d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
8 locks held by kworker/u8:0/19291:
#0: ffff88801c2ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90003707c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fbbe770 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffff8880213ee0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff8880213ee0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff8880213ee0e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:504
#4: ffff8880213ef250 (&devlink->lock_key#11){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:274 [inline]
#4: ffff8880213ef250 (&devlink->lock_key#11){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff8880213ef250 (&devlink->lock_key#11){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:504
#5: ffffffff8fbcd588 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1178
#6: ffff888035178d50 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2789 [inline]
#6: ffff888035178d50 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x583/0x2380 net/core/dev.c:12375
#7: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#7: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.5.3632/20295:
#0: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
4 locks held by syz.1.3653/20361:
#0: ffff88802b678ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline]
#0: ffff88802b678ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716
#1: ffff88802b6780c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346
#2: ffffffff8fd59be8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff8fd59be8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644
#3: ffff88804b2cbaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 net/bluetooth/l2cap_core.c:1755
=============================================
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 01/24/2026
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:161 [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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ce 6c 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 6d 1b 00 fb f4 7c ea 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000246
RAX: 00000000032e7fdb RBX: ffffffff819a924d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8def38f2 RDI: ffffffff8c27ab00
RBP: ffffffff8e407eb0 R08: ffff8880b863395b R09: 1ffff110170c672b
R10: dffffc0000000000 R11: ffffed10170c672c R12: ffffffff901195b0
R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000005989c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1bd/0x500 kernel/sched/idle.c:332
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:760
start_kernel+0x385/0x3d0 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147