INFO: task syz.0.2392:15044 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.0.2392 state:D stack:28856 pid:15044 tgid:15043 ppid:5602 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+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f70e3b9e0d9
RSP: 002b:00007f70e4a56028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffe RBX: 00007f70e3e25fa0 RCX: 00007f70e3b9e0d9
RDX: 0000200000000040 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f70e3c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f70e3e26038 R14: 00007f70e3e25fa0 R15: 00007ffc5b018b58
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/0:2/187:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc9000301fd08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
2 locks held by getty/5347:
#0: ffff8880330d10a0 (&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
3 locks held by kworker/u9:2/5593:
#0: ffff88805ea59140 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc900030bfd08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff888055838ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331
3 locks held by kworker/1:4/5777:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90002e3fd08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff8ebf3ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz-executor/8584:
#0: ffff88807c0ca0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807c0ca0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807c0ca0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807c0ca0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
3 locks held by syz.5.2304/14798:
#0: ffff88807f1700f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88807d3f4450 (sb_writers#26){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860
2 locks held by syz.0.2392/15044:
#0: ffff8880369b40d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880369b40d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880369b40d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880369b40d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15111:
#0: ffff88807a4400d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807a4400d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807a4400d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807a4400d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15265:
#0: ffff888039dee0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888039dee0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888039dee0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff888039dee0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15396:
#0: ffff8880397be0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880397be0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880397be0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880397be0d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15530:
#0: ffff8880264980d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880264980d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880264980d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880264980d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15706:
#0: ffff88802bc080d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802bc080d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802bc080d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802bc080d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15862:
#0: ffff88807d3f00d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807d3f00d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807d3f00d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807d3f00d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/15930:
#0: ffff88803fc000d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88803fc000d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88803fc000d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88803fc000d8 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
1 lock held by syz-executor/16493:
#0: ffff888056264ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
1 lock held by syz-executor/16576:
#0: ffff88804893cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
1 lock held by syz-executor/16708:
#0: ffff88809864cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
1 lock held by syz-executor/17134:
#0: ffffffff8ebf3ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 0
CPU: 0 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 07/16/2026
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17134 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:unwind_next_frame+0x22/0x2090 arch/x86/kernel/unwind_orc.c:485
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 57 48 89 fa 41 56 48 c1 ea 03 41 55 49 89 fd 41 54 55 53 <48> 83 ec 38 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 42 0b 00 00 41 8b
RSP: 0018:ffffc90006a875c0 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffffc90006a875f8 RCX: ffffc90006a8754c
RDX: 1ffff92000d50ebf RSI: ffffffff81aad4b1 RDI: ffffc90006a875f8
RBP: ffffc90006a87688 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000cc1e R12: ffffffff81f48120
R13: ffffc90006a875f8 R14: 0000000000000000 R15: ffff8880207b0000
FS: 0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f198808a78 CR3: 0000000036da9000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
__free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
__free_contig_range mm/page_alloc.c:6942 [inline]
free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461
vfree mm/vmalloc.c:3510 [inline]
vfree+0x107/0x750 mm/vmalloc.c:3484
kcov_put kernel/kcov.c:447 [inline]
kcov_put kernel/kcov.c:443 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:554
__fput+0x3ff/0xb50 fs/file_table.c:512
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x951/0x2ae0 kernel/exit.c:1009
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 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+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8dba95e90e
Code: Unable to access opcode bytes at 0x7f8dba95e8e4.
RSP: 002b:00007ffd049e1718 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: 0000000000000020 RBX: 000055556b687500 RCX: 00007f8dba95e90e
RDX: 0000000000000020 RSI: 00007f8dbb754670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd049e1794 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f8dbb754670 R15: 0000000000000000