INFO: task syz-executor:15173 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-
task:syz-executor state:D stack:22288 pid:15173 tgid:15173 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1372
deactivate_locked_super+0xbc/0x110 fs/super.c:589
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
task_work_run+0x1d9/0x270 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+0x204/0x770 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:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7bc9b9f397
RSP: 002b:00007ffe0296bc48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7bc9c344bb RCX: 00007f7bc9b9f397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe0296bd00
RBP: 00007ffe0296bd00 R08: 00007ffe0296cd00 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe0296cd90
R13: 00007f7bc9c344bb R14: 0000000000168583 R15: 00007ffe0296cdd0
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5370: 2, on CPU#0:
#0: ffff888027f0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/15105: 2, on CPU#0:
#0: ffff888034d480e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888034d480e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888034d480e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/15173: 2, on CPU#1:
#0: ffff88807bdee0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807bdee0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807bdee0e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by kworker/0:4/15669: 6, on CPU#0:
#0: ffff888022ec1d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888022ec1d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888022ec1d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888022ec1d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90004a0fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004a0fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004a0fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90004a0fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff88802943c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802943c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
#3: ffff888029487568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3265 [inline]
#3: ffff888029487568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5477 [inline]
#3: ffff888029487568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#3: ffff888029487568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#3: ffff888029487568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5966
#4: ffff8880292c3d60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5478 [inline]
#4: ffff8880292c3d60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#4: ffff8880292c3d60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#4: ffff8880292c3d60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5966
#5: ffffffff8fafd508 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x1810 drivers/usb/core/hub.c:3080
locks held by syz-executor/16595: 2, on CPU#0:
#0: ffff888042ee80e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888042ee80e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888042ee80e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/17094: 2, on CPU#0:
#0: ffff88802ec2c0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88802ec2c0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88802ec2c0e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz.2.2455/18580: 3, on CPU#0:
#0: ffff8880288e15f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff888053aea460 (sb_writers#38){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff888053aea460 (sb_writers#38){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by syz-executor/18865: 2, on CPU#0:
#0: ffff888026f360e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888026f360e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888026f360e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/19115: 2, on CPU#0:
#0: ffff88807f5960e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807f5960e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807f5960e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/19167: 2, on CPU#1:
#0: ffff888033dbe0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888033dbe0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888033dbe0e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/19224: 2, on CPU#1:
#0: ffff88805fe280e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88805fe280e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88805fe280e8 (&type->s_umount_key#97){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f09f5c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz.7.2899/21014: 2, on CPU#1:
#0: ffff888042fd4460 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1158
#1: ffff88807bdee0e8 (&type->s_umount_key#97){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#1: ffff88807bdee0e8 (&type->s_umount_key#97){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124
locks held by syz.4.2959/21203: 1, on CPU#1:
#0: ffffffff8ed62ce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8ed62ce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:966
locks held by syz.4.2959/21209: 3, last CPU#1:
#0: ffff88807f949d38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff88807f949d38 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
#1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
#2: ffff888075b98618 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline]
#2: ffff888075b98618 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 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: 21209 Comm: syz.4.2959 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:lock_acquire+0xcd/0x350 kernel/locking/lockdep.c:5943
Code: a4 0b 00 00 00 0f 85 c0 00 00 00 48 89 5c 24 08 4c 89 fb 9c 41 5f fa 48 c7 c7 04 f9 42 8e e8 fa cb 42 0a 65 ff 05 4b 5d f2 11 <45> 31 c9 4c 89 7c 24 10 41 f7 c7 00 02 00 00 41 0f 94 c1 8b 85 a8
RSP: 0018:ffffc9000387f280 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 8000000000000002
RDX: 0000000000000000 RSI: ffffffff8e42f904 RDI: ffffffff8c6da780
RBP: ffff8880338f9f40 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff940002f61a9 R12: ffffffff8ed5c9e0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff888124dcb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c467e85 CR3: 0000000079549000 CR4: 0000000000350ef0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:947 [inline]
pfn_valid+0xd6/0x490 include/linux/mmzone.h:2276
page_table_check_clear+0x21/0x500 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:879 [inline]
zap_present_folio_ptes mm/memory.c:1779 [inline]
zap_present_ptes mm/memory.c:1861 [inline]
do_zap_pte_range mm/memory.c:1963 [inline]
zap_pte_range mm/memory.c:2065 [inline]
zap_pmd_range mm/memory.c:2151 [inline]
zap_pud_range mm/memory.c:2179 [inline]
zap_p4d_range mm/memory.c:2200 [inline]
__zap_vma_range+0x3a12/0x4f80 mm/memory.c:2240
unmap_vmas+0x390/0x550 mm/memory.c:2309
exit_mmap+0x293/0x9f0 mm/mmap.c:1315
__mmput+0x118/0x420 kernel/fork.c:1193
exit_mm+0x221/0x2d0 kernel/exit.c:618
do_exit+0x6cd/0x2360 kernel/exit.c:1000
do_group_exit+0x22d/0x2f0 kernel/exit.c:1155
get_signal+0x121b/0x12c0 kernel/signal.c:3112
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 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:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc30039e159
Code: Unable to access opcode bytes at 0x7fc30039e12f.
RSP: 002b:00007fc2fe5f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc300626098 RCX: 00007fc30039e159
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc300626098
RBP: 00007fc300626090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc300626128 R14: 00007ffe4e222cd0 R15: 00007ffe4e222db8