INFO: task syz.2.3512:23363 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3512 state:D stack:26120 pid:23363 tgid:23359 ppid:16784 task_flags:0x400740 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
coredump_wait fs/coredump.c:534 [inline]
vfs_coredump+0x848/0x55e0 fs/coredump.c:1196
get_signal+0x22e1/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43fbd8f7c9
RSP: 002b:00007f43fcc5f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f43fbfe6188 RCX: 00007f43fbd8f7c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f43fbfe618c
RBP: 00007f43fbfe6180 R08: 00007f43fcca2000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43fbfe6218 R14: 00007fff600f71a0 R15: 00007fff600f7288
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:7/5920:
#0: ffff88813ff55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000439fc90 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by getty/17166:
#0: ffff888031c190a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900042f32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
3 locks held by kworker/u10:14/18720:
#0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000440fc90 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
3 locks held by kworker/u10:18/19861:
#0: ffff888031023948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90004bcfc90 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14f0 net/ipv6/addrconf.c:4194
1 lock held by syz.2.3512/23360:
2 locks held by syz-executor/23650:
#0: ffff888071db40e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888071db40e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888071db40e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888071db40e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e8011e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.3.3583/23709:
2 locks held by syz.4.3603/23816:
#0: ffffffff901eb410 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e8011e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
2 locks held by syz-executor/23913:
#0: ffff8880400d80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880400d80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880400d80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880400d80e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e8011e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/24021:
#0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
#1: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz-executor/24735:
#0: ffff88808c1180e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88808c1180e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88808c1180e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88808c1180e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e8011e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
4 locks held by syz-executor/25281:
#0: ffff88807ef0cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xc0 net/bluetooth/hci_core.c:499
#1: ffff88807ef0c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3af/0x1260 net/bluetooth/hci_sync.c:5314
#2: ffffffff903c1d88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
#2: ffffffff903c1d88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x290 net/bluetooth/hci_conn.c:2637
#3: ffff888033bc1b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x760 net/bluetooth/l2cap_core.c:1763
3 locks held by syz.1.3933/25510:
#0: ffff88805b951348 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88805b951348 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:661
#1: ffffffff901e9030 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain kernel/notifier.c:379 [inline]
#1: ffffffff901e9030 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368
#2: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x4d/0x3a0 net/mac80211/main.c:1673
1 lock held by syz.1.3933/25514:
#0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
2 locks held by syz.9.3934/25519:
#0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577
#1: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21d/0x7d0 net/ipv4/ip_tunnel.c:1146
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246