INFO: task syz-executor:5633 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-executor state:D stack:22024 pid:5633 tgid:5633 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1365
deactivate_locked_super+0xc1/0x1b0 fs/super.c:477
deactivate_super fs/super.c:510 [inline]
deactivate_super+0xe7/0x110 fs/super.c:506
cleanup_mnt+0x21f/0x450 fs/namespace.c:1317
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x652/0x840 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ee479f0d7
RSP: 002b:00007fff5d33e478 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8ee479f0d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff5d33e530
RBP: 00007fff5d33e530 R08: 00007fff5d33f530 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5d33f5c0
R13: 00007f8ee483330a R14: 0000000000026926 R15: 00007fff5d33f600
Showing all locks held in the system:
2 locks held by rcu_exp_gp_kthr/19:
#0: ffff8880b843b660 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:675 [inline]
#0: ffff8880b843b660 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:659
#1: ffff88802b4f8008 (&____s->seqcount#15){.---}-{0:0}, at: trace_find_filtered_pid kernel/trace/trace_pid.c:15 [inline]
#1: ffff88802b4f8008 (&____s->seqcount#15){.---}-{0:0}, at: trace_ignore_this_task+0xbc/0x100 kernel/trace/trace_pid.c:44
1 lock held by khungtaskd/32:
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe5f80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/4958:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90002e9fd08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff8ebf18f8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
2 locks held by getty/5383:
#0: ffff888036f980a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5633:
#0: ffff8880528e80d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880528e80d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880528e80d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880528e80d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f360 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/5640:
#0: ffff888058dd00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888058dd00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888058dd00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888058dd00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f360 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
4 locks held by kworker/u8:21/5903:
#0: ffff88801caf6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90004c9fd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff90a86408 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff8ebf1a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by kworker/u8:27/5909:
#0: ffff8880315fb140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90004cffd08 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4769
2 locks held by syz.2.131/6459:
#0: ffffffff90b4dc08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f06f360 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz-executor/6589:
#0: ffff88802afe00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802afe00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802afe00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802afe00d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f360 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/6729:
#0: ffff888079a9a0d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888079a9a0d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888079a9a0d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888079a9a0d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f06f360 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by kworker/u8:29/6809:
#0: ffff88801f32b940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc9000343fd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
1 lock held by syz-executor/7091:
#0: ffff88807a680ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
1 lock held by syz-executor/8142:
#0: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8bb/0x2380 net/core/rtnetlink.c:4158
3 locks held by syz.5.434/8246:
#0: ffffffff90a86408 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x90/0xc10 net/core/dev.c:13085
#2: ffffffff8ebf1a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.7.435/8255:
#0: ffffffff90a86408 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1149
2 locks held by syz.1.436/8258:
#0: ffffffff90a86408 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90a9f000 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:4017
3 locks held by rm/8273:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x21c/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 4977 Comm: syslogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:__bfs+0x1c7/0x2a0 kernel/locking/lockdep.c:1815
Code: 81 e3 ff 0f 00 00 39 1d 67 6b 85 14 48 89 04 f5 80 ee 24 97 73 11 89 1d 57 6b 85 14 eb 09 0f 1f 44 00 00 4c 89 78 30 48 8b 00 <4c> 39 c0 75 f4 e9 22 ff ff ff b8 01 00 00 00 48 83 c4 30 5b 5d 41
RSP: 0018:ffffc900026ef3f8 EFLAGS: 00000006
RAX: ffffffff967332b8 RBX: 0000000000000225 RCX: 0000000000000226
RDX: 0000000000000000 RSI: 0000000000000226 RDI: ffffffff980acbd8
RBP: 0000000000000030 R08: ffffffff967332b8 R09: 0000000000000002
R10: ffffc900026ef588 R11: 0000000000000000 R12: ffffffff81e465a0
R13: ffffc900026ef4a0 R14: ffffffff81e473b0 R15: ffffffff980acbd8
FS: 00007f16e2efec80(0000) GS:ffff888123dee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007face5d95e9c CR3: 000000007ed40000 CR4: 00000000003526f0
Call Trace:
__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
check_irq_usage+0xe5/0x810 kernel/locking/lockdep.c:2796
check_prev_add+0xfe/0xe60 kernel/locking/lockdep.c:3169
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
seqcount_lockdep_reader_access include/linux/seqlock.h:73 [inline]
trace_pid_list_is_set+0xfb/0x390 kernel/trace/pid_list.c:143
trace_find_filtered_pid kernel/trace/trace_pid.c:15 [inline]
trace_ignore_this_task+0xbc/0x100 kernel/trace/trace_pid.c:44
event_filter_pid_sched_wakeup_probe_post kernel/trace/trace_events.c:1157 [inline]
event_filter_pid_sched_wakeup_probe_post+0x11f/0x270 kernel/trace/trace_events.c:1143
__traceiter_sched_wakeup+0x55/0x90 include/trace/events/sched.h:178
__do_trace_sched_wakeup include/trace/events/sched.h:178 [inline]
trace_sched_wakeup+0xec/0x160 include/trace/events/sched.h:178
ttwu_do_wakeup kernel/sched/core.c:3730 [inline]
ttwu_do_activate+0x219/0x800 kernel/sched/core.c:3827
ttwu_queue kernel/sched/core.c:4077 [inline]
try_to_wake_up+0xce0/0x1c90 kernel/sched/core.c:4415
autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:403
__wake_up_common+0x135/0x1f0 kernel/sched/wait.c:108
__wake_up_common_lock kernel/sched/wait.c:125 [inline]
__wake_up_sync_key+0x36/0x50 kernel/sched/wait.c:192
__unix_dgram_recvmsg+0x31a/0xc30 net/unix/af_unix.c:2607
unix_dgram_recvmsg+0xcd/0x100 net/unix/af_unix.c:2681
sock_recvmsg_nosec net/socket.c:1126 [inline]
sock_recvmsg+0x1d5/0x220 net/socket.c:1148
sock_read_iter+0x2b0/0x3a0 net/socket.c:1217
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x960/0xb40 fs/read_write.c:574
ksys_read+0x1f8/0x250 fs/read_write.c:716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f16e304e407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffcacfd15a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f16e2efec80 RCX: 00007f16e304e407
RDX: 00000000000000ff RSI: 0000561f9d776950 RDI: 0000000000000000
RBP: 0000561f9d776910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000561f9d7769d9
R13: 0000000000000000 R14: 0000561f9d776950 R15: 0000561f6606ad98