INFO: task syz.2.4319:25600 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.4319 state:D stack:27672 pid:25600 tgid:25600 ppid:17037 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbe/0x1a0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xde/0x100 fs/super.c:503
cleanup_mnt+0x225/0x450 fs/namespace.c:1417
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86c/0x2bd0 kernel/exit.c:964
do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f306efc11e5
RSP: 002b:00007f306feb5f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f306f1b6080 RCX: 00007f306efc11e5
RDX: 00007f306feb5fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f306f010ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f306f1b6080 R15: 00007ffecfee4e88
INFO: task syz.3.4627:26943 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.4627 state:D stack:27280 pid:26943 tgid:26943 ppid:16662 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
deactivate_locked_super+0xbe/0x1a0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xde/0x100 fs/super.c:503
cleanup_mnt+0x225/0x450 fs/namespace.c:1417
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86c/0x2bd0 kernel/exit.c:964
do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4deb7c11e5
RSP: 002b:00007f4dec68af80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 00007f4deb9b6160 RCX: 00007f4deb7c11e5
RDX: 00007f4dec68afc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4deb810ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f4deb9b6160 R15: 00007fff72fa49d8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by syz.2.4319/25600:
#0: ffff888072a880e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888072a880e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888072a880e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888072a880e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de628 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.3.4627/26943:
#0: ffff888033d480e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888033d480e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888033d480e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888033d480e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de628 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.4.4652/27051:
#0:
ffffffff90408f90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de628 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
7 locks held by kworker/u10:13/28602:
2 locks held by getty/29354:
#0: ffff888031f840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e732f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
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: 0 Comm: swapper/0 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 1b 6f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 97 25 00 fb f4 8c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6
RAX: 000000000093d877 RBX: 0000000000000000 RCX: ffffffff8b847c69
RDX: 0000000000000000 RSI: ffffffff8de2c794 RDI: ffffffff8c157960
RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645
R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e297780 R14: ffffffff90a9a150 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124720000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3350aff8 CR3: 0000000079d1e000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:749
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
rest_init+0x16b/0x2b0 init/main.c:745
start_kernel+0x3ee/0x4d0 init/main.c:1102
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x148