INFO: task syz.0.7857:22137 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.7857 state:D stack:28504 pid:22137 tgid:22136 ppid:5617 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x16ec/0x5620 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1662
__rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819
__rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1364
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
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:67 [inline]
exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
__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+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f262becce59
RSP: 002b:00007f262a11e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffec RBX: 00007f262c145fa0 RCX: 00007f262becce59
RDX: 0000200000000040 RSI: 00002000000001c0 RDI: 0000000000000000
RBP: 00007f262bf62d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000001000016 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f262c146038 R14: 00007f262c145fa0 R15: 00007fffd12322e8
Showing all locks held in the system:
3 locks held by ksoftirqd/0/15:
5 locks held by ksoftirqd/1/30:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by udevd/4970:
2 locks held by getty/5354:
#0: ffff888036e350a0 (&tty->ldisc_sem){+[ 1030.577177][ T38] #0: ffff888036e350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5616:
2 locks held by syz.2.6173/18644:
#0: ffffffff8f3bf680 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e8598 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b9/0xc20 fs/nfsd/nfsctl.c:1644
2 locks held by syz.0.7857/22137:
#0: ffff888039b9c0d0 (&type->s_umount_key#100){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888039b9c0d0 (&type->s_umount_key#100){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888039b9c0d0 (&type->s_umount_key#100){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffffffff8e2e8598 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:576
2 locks held by syz.5.9030/24569:
#0: ffffffff8f3bf680 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e2e8598 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1738
2 locks held by syz-executor/24986:
#0: ffff88803045a480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888063830388 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#1: ffff888063830388 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
#1: ffff888063830388 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline]
#1: ffff888063830388 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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:162 [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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26227 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:kernel_text_address+0x0/0xe0 kernel/extable.c:95
Code: c1 48 81 fb 20 6d f8 90 0f 92 c2 20 ca 08 c2 0f b6 c2 5b c3 cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 55 41 56 53 48 81 ff 00 00 00 81 0f 93 c0 48 81 ff 10
RSP: 0000:ffffc9001d84f490 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8230dd0d RCX: 0000000000000046
RDX: 0000000000000001 RSI: ffffffff8d85e9a4 RDI: ffffffff8230dd0d
RBP: ffffc9001d84f550 R08: ffffc9001d84f730 R09: 0000000000000000
R10: ffffc9001d84f518 R11: fffff52003b09ea5 R12: ffff888038250000
R13: 1ffff1100704a0be R14: dffffc0000000000 R15: 1ffff92003b09ea2
FS: 000055558bf2b500(0000) GS:ffff888126186000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94633458d2 CR3: 000000003cd98000 CR4: 00000000003526f0
Call Trace:
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x28b2/0x2930 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2490
alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
alloc_pages_noprof+0xd2/0x2f0 mm/mempolicy.c:2581
pagetable_alloc_noprof include/linux/mm.h:3651 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:76 [inline]
pte_alloc_one+0x22/0x380 arch/x86/mm/pgtable.c:18
do_fault_around mm/memory.c:5861 [inline]
do_read_fault mm/memory.c:5900 [inline]
do_fault mm/memory.c:6043 [inline]
do_pte_missing+0x126d/0x2950 mm/memory.c:4566
handle_pte_fault mm/memory.c:6427 [inline]
__handle_mm_fault mm/memory.c:6565 [inline]
handle_mm_fault+0xd30/0x1400 mm/memory.c:6734
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f94633458d2
Code: Unable to access opcode bytes at 0x7f94633458a8.
RSP: 002b:00007fff8f0ee7e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007fff8f0ee7e0 RCX: 00007f94633458d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff8f0ee96c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558bf2b7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000ed130 R15: 00007fff8f0ee9c0