INFO: task syz-executor:15771 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24104 pid:15771 tgid:15771 ppid:1 task_flags:0x400140 flags:0x00004004 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 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114 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: 0033:0x7f321fb8fc57 RSP: 002b:00007ffef1a5fd18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f321fc10925 RCX: 00007f321fb8fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffef1a5fdd0 RBP: 00007ffef1a5fdd0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffef1a60e60 R13: 00007f321fc10925 R14: 000000000008eb6e R15: 00007ffef1a60ea0 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 getty/5609: #0: ffff88814c9fd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5835: 2 locks held by syz-executor/5844: #0: ffff8880296a40e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880296a40e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880296a40e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880296a40e0 (&type->s_umount_key#53){++++}-{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-executor/5849: #0: ffff8880796600e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880796600e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880796600e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880796600e0 (&type->s_umount_key#53){++++}-{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-executor/5856: #0: ffff888048b380e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888048b380e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888048b380e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888048b380e0 (&type->s_umount_key#53){++++}-{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 kworker/u10:33/9402: #0: ffff888022301948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90004e17d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 2 locks held by syz.3.1283/15555: #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_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629 2 locks held by syz-executor/15771: #0: ffff888058a620e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888058a620e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888058a620e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888058a620e0 (&type->s_umount_key#53){++++}-{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-executor/16662: #0: ffff8880287bc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880287bc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880287bc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880287bc0e0 (&type->s_umount_key#53){++++}-{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-executor/17063: #0: ffff888058a0c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888058a0c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888058a0c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888058a0c0e0 (&type->s_umount_key#53){++++}-{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-executor/17445: #0: ffff88807e3fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807e3fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807e3fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88807e3fc0e0 (&type->s_umount_key#53){++++}-{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-executor/17923: #0: ffff88807cf060e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807cf060e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807cf060e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88807cf060e0 (&type->s_umount_key#53){++++}-{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-executor/18286: #0: ffff88803bcf40e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803bcf40e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803bcf40e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88803bcf40e0 (&type->s_umount_key#53){++++}-{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-executor/18743: #0: ffff88802564c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802564c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802564c0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88802564c0e0 (&type->s_umount_key#53){++++}-{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-executor/19051: #0: ffff888044a940e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888044a940e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888044a940e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888044a940e0 (&type->s_umount_key#53){++++}-{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-executor/19580: #0: ffff8880467fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880467fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880467fc0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880467fc0e0 (&type->s_umount_key#53){++++}-{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-executor/19953: #0: ffff88803bb0a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803bb0a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803bb0a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88803bb0a0e0 (&type->s_umount_key#53){++++}-{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.5.1445/21529: #0: ffff88805baa60e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805baa60e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805baa60e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88805baa60e0 (&type->s_umount_key#53){++++}-{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-executor/21561: #0: ffff888083f620e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888083f620e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888083f620e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888083f620e0 (&type->s_umount_key#53){++++}-{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-executor/22330: #0: ffff88806a4640e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88806a4640e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88806a4640e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88806a4640e0 (&type->s_umount_key#53){++++}-{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-executor/22373: #0: ffff8880598e60e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880598e60e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880598e60e0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880598e60e0 (&type->s_umount_key#53){++++}-{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 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller #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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc6-syzkaller #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:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000000596e95 RBX: 0000000000000001 RCX: ffffffff8b847c69 RDX: 0000000000000000 RSI: ffffffff8de2c764 RDI: ffffffff8c1578e0 RBP: ffffed1003cd7b40 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e6bda00 R14: ffffffff90a9a150 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124820000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fca2763000 CR3: 0000000035a44000 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 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148