INFO: task syz-executor:5840 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22616 pid:5840 tgid:5840 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1347 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super fs/super.c:506 [inline] deactivate_super+0xde/0x100 fs/super.c:502 cleanup_mnt+0x225/0x450 fs/namespace.c:1327 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x419/0x4b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03cc1901f7 RSP: 002b:00007ffe735a8698 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f03cc211d7d RCX: 00007f03cc1901f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe735a8750 RBP: 00007ffe735a8750 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe735a97e0 R13: 00007f03cc211d7d R14: 000000000005d903 R15: 00007ffe735a9820 INFO: task syz.0.938:16659 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.938 state:D stack:27640 pid:16659 tgid:16651 ppid:5855 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa8eed8eec9 RSP: 002b:00007fa8efbc8038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa8eefe6090 RCX: 00007fa8eed8eec9 RDX: 0000000000000080 RSI: 0000200000000140 RDI: 0000000000000006 RBP: 00007fa8eee11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa8eefe6128 R14: 00007fa8eefe6090 R15: 00007fff102d8e88 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e1cd7b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by khungtaskd/31: #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e1c2220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by syz-executor/5840: #0: ffff88807baf00e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807baf00e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807baf00e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88807baf00e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz-executor/5846: #0: ffff8880305240e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880305240e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880305240e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880305240e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz.0.938/16652: #0: ffffffff8ff8c250 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 2 locks held by syz.0.938/16659: #0: ffffffff8ff8c250 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 2 locks held by getty/17320: #0: ffff88814d09c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90003a732f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/17455: #0: ffff888012a020e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888012a020e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888012a020e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888012a020e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz-executor/18572: #0: ffff8880585680e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880585680e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880585680e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880585680e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e5e9848 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 4 locks held by kworker/u8:22/21235: #0: ffff88801bedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9001a53fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff8fed24d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669 #3: ffffffff8fee8908 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x8b/0xaf0 net/core/dev.c:12807 1 lock held by syz.8.1413/24570: 1 lock held by syz.8.1462/25121: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 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: 6499 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:kasan_check_byte include/linux/kasan.h:401 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5842 [inline] RIP: 0010:lock_acquire+0xf4/0x350 kernel/locking/lockdep.c:5825 Code: 44 89 f2 48 89 de e8 5b d0 fe ff 5f 41 58 65 ff 0d 51 34 e4 11 0f 85 4f ff ff ff e8 76 f2 94 ff e9 45 ff ff ff 48 8b 74 24 68 <48> 89 df e8 54 0b 8b 00 8b 0d d2 45 c9 0e 85 c9 0f 84 b1 00 00 00 RSP: 0018:ffffc9000eedfb88 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8880213006e8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b50cef6 RDI: ffffffff8dac7e40 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff905ff197 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124e6f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000051a000 CR3: 000000003220e000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] cfg80211_wiphy_work+0xf2/0x580 net/wireless/core.c:425 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245