INFO: task syz.2.680:8629 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.680 state:D stack:27208 pid:8629 tgid:8628 ppid:5829 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_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 genl_family_rcv_msg_doit+0x209/0x2f0 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+0x5aa/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+0xa98/0xc70 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66f3d8f749 RSP: 002b:00007f66f4ccd038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f66f3fe5fa0 RCX: 00007f66f3d8f749 RDX: 0000000020000000 RSI: 0000200000005380 RDI: 0000000000000006 RBP: 00007f66f3e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f66f3fe6038 R14: 00007f66f3fe5fa0 R15: 00007ffc76b1dbb8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:3/50: 3 locks held by kworker/u8:8/2993: #0: ffff88814cb2f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000b8a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900eb2c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900eb2c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14e0 net/ipv6/addrconf.c:4194 2 locks held by getty/5586: #0: ffff88814cf240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5825: #0: ffff88805974e0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805974e0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805974e0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88805974e0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz-executor/5837: #0: ffff88802a6300e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802a6300e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802a6300e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88802a6300e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 3 locks held by kworker/1:4/5874: #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000428fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/0:3/5912: #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900044cfd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff888027fd2240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b6/0x6da0 drivers/net/netdevsim/fib.c:1490 5 locks held by kworker/u8:11/6311: #0: ffff88801ba9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90003effd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900d4e90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669 #3: ffffffff900eb2c8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff900eb2c8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248 #4: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by syz.0.677/8622: #0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 2 locks held by syz.2.680/8629: #0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 2 locks held by syz-executor/8813: #0: ffff8880257e60e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880257e60e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880257e60e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880257e60e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 3 locks held by syz.5.965/9913: #0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88804fdeb6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2406 #2: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb6/0x1170 fs/nfsd/nfsctl.c:1477 2 locks held by syz-executor/9946: #0: ffff8880256dc0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880256dc0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880256dc0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880256dc0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz-executor/10099: #0: ffff8880255a20e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880255a20e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880255a20e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880255a20e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 4 locks held by syz-executor/10190: #0: ffff888028f78dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff888028f780b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5296 #2: ffffffff9035f208 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2119 [inline] #2: ffffffff9035f208 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2614 #3: ffff8880790a6338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1763 2 locks held by syz-executor/10249: #0: ffff88807004a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807004a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807004a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88807004a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz-executor/10804: #0: ffff88804d14c0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88804d14c0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88804d14c0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff88804d14c0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 ============================================= 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 10/25/2025 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+0x675/0x7d0 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: 5913 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events drain_vmap_area_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:__unwind_start+0x48c/0x7f0 arch/x86/kernel/unwind_orc.c:756 Code: 48 c1 e8 03 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 14 02 00 00 41 8b 06 85 c0 0f 84 56 fe ff ff 41 80 7d 00 00 0f 85 24 02 00 00 <41> 80 3c 24 00 49 8b 46 08 0f 85 fc 01 00 00 49 8b 56 10 48 39 c3 RSP: 0018:ffffc9000441f630 EFLAGS: 00000246 RAX: 1ffff92000883ed2 RBX: ffffc9000441f710 RCX: ffffc90004420000 RDX: 0000000000000001 RSI: ffff88802fca3c80 RDI: ffffc9000441f630 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc9000441f680 R11: 0000000000000001 R12: fffff52000883ed2 R13: fffff52000883ed1 R14: ffffc9000441f680 R15: ffffc9000441f688 FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055cfa5e1c000 CR3: 000000000e182000 CR4: 00000000003526f0 Call Trace: unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901 kasan_depopulate_vmalloc_pte+0x5b/0x80 mm/kasan/shadow.c:495 apply_to_pte_range mm/memory.c:3143 [inline] apply_to_pmd_range mm/memory.c:3187 [inline] apply_to_pud_range mm/memory.c:3223 [inline] apply_to_p4d_range mm/memory.c:3259 [inline] __apply_to_page_range+0xac1/0x13f0 mm/memory.c:3295 kasan_release_vmalloc+0xd1/0xe0 mm/kasan/shadow.c:616 kasan_release_vmalloc_node mm/vmalloc.c:2255 [inline] purge_vmap_node+0x1c4/0xa30 mm/vmalloc.c:2272 __purge_vmap_area_lazy+0xa06/0xc60 mm/vmalloc.c:2362 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2396 process_one_work+0x9cf/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+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vkms_vblank_simulate: vblank timer overrun