INFO: task syz.3.3512:24437 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3512 state:D stack:26056 pid:24437 tgid:24433 ppid:16358 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 nfsd_nl_rpc_status_get_dumpit+0xb7/0x1200 fs/nfsd/nfsctl.c:1510 genl_dumpit+0x125/0x230 net/netlink/genetlink.c:1026 netlink_dump+0x532/0xd00 net/netlink/af_netlink.c:2331 __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2446 genl_family_rcv_msg_dumpit+0x1e2/0x2e0 net/netlink/genetlink.c:1075 genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline] genl_rcv_msg+0x471/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738 __sys_sendmsg+0x160/0x210 net/socket.c:2770 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9f79b9ce59 RSP: 002b:00007f9f7a9b0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9f79e16090 RCX: 00007f9f79b9ce59 RDX: 0000000020000000 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f9f79c32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9f79e16128 R14: 00007f9f79e16090 R15: 00007ffdaacc5cb8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5383: #0: ffff8880368010a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 2 locks held by kworker/0:3/5699: #0: ffff88813fe6b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90004577d08 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by kworker/u10:40/18163: #0: ffff88801ef7d140 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900038c7d08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 4 locks held by kworker/u10:41/18165: #0: ffff88801c6c6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90003887d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673 #3: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: cangw_pernet_exit_batch+0x15/0xa0 net/can/gw.c:1294 2 locks held by syz-executor/18619: #0: ffff8880348900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880348900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880348900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff8880348900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz.6.3427/23976: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660 2 locks held by syz-executor/24254: #0: ffff888067b000d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888067b000d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888067b000d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff888067b000d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 3 locks held by syz.3.3512/24437: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff88802b99d6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2410 #2: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb7/0x1200 fs/nfsd/nfsctl.c:1510 2 locks held by syz-executor/24998: #0: ffff88807af480d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807af480d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807af480d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff88807af480d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz-executor/26132: #0: ffff8880553260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880553260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880553260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff8880553260d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz.9.3761/26175: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 2 locks held by syz.8.3770/26280: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660 2 locks held by syz.1.3795/26561: #0: ffff8880338aa0d8 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super fs/super.c:345 [inline] #0: ffff8880338aa0d8 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: sget_fc+0x3c8/0x1d80 fs/super.c:766 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 1 lock held by syz.5.3836/27103: #0: ffff88807af24ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497 3 locks held by syz.7.3843/27134: #0: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 #1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 #2: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.3.3844/27143: #0: ffff888042ba4ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497 2 locks held by syz.6.3845/27140: #0: ffffffff906288e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 #1: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:4017 1 lock held by dhcpcd/27148: #0: ffff88808fa3e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88808fa3e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf50 net/packet/af_packet.c:3204 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245