INFO: task syz.4.3421:18705 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3421 state:D stack:27168 pid:18705 tgid:18704 ppid:16954 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efd0419cdd9 RSP: 002b:00007efd04f78028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007efd04415fa0 RCX: 00007efd0419cdd9 RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000005 RBP: 00007efd04232d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd04416038 R14: 00007efd04415fa0 R15: 00007ffea8385938 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5382: #0: ffff888035de70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:16/5954: #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005417c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005417c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fdc0c28 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 3 locks held by kworker/u8:26/6300: #0: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8e7eb750 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222 4 locks held by kworker/u8:34/6309: #0: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880750d0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6645 [inline] #2: ffff8880750d0780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x460 net/wireless/core.c:499 #3: ffffffff9a6bf4d0 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x83/0x580 lib/debugobjects.c:835 2 locks held by syz.0.3289/18043: #0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633 2 locks held by syz.4.3421/18705: #0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633 2 locks held by syz.1.3863/20307: #0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938 2 locks held by kworker/0:6/20371: #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005c77c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005c77c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 6 locks held by kworker/u9:0/21698: #0: ffff888080986140 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888080986140 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900039cfc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900039cfc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888052b8cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff888052b8c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5744 #4: ffffffff8ff52ce0 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff8ff52ce0 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x340 net/bluetooth/hci_conn.c:1409 #5: ffff88807d3762f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1777 2 locks held by syz.7.4533/22654: #0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938 1 lock held by syz.2.4543/22701: #0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 5654 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:memset_orig+0x75/0xb0 arch/x86/lib/memset_64.S:92 Code: 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 66 0f 1f 44 00 00 ff c9 48 89 07 <48> 8d 7f 08 75 f5 83 e2 07 74 0a ff ca 88 07 48 8d 7f 01 75 f6 4c RSP: 0018:ffffc90003b1fd78 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc90003b1fe60 RCX: 0000000000000001 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90003b1fda0 RBP: ffffc90003b1fe10 R08: ffffc90003b1fdaf R09: 0000000000000000 R10: ffffc90003b1fda0 R11: fffff52000763fb6 R12: 1ffff92000763fb0 R13: dffffc0000000000 R14: 00007ffebc6ac3a0 R15: ffffc90003b1fda0 FS: 00005555922d7540(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000e038 CR3: 000000007ee38000 CR4: 00000000003526f0 Call Trace: get_timespec64+0x86/0x1b0 kernel/time/time.c:870 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1380 [inline] __se_sys_clock_nanosleep+0x1ce/0x3b0 kernel/time/posix-timers.c:1368 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdefd757f57 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffebc6ac360 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00005555922d7540 RCX: 00007fdefd757f57 RDX: 00007ffebc6ac3a0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffebc6ac880 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffebc6ac3dc R14: 00007ffebc6ac470 R15: 0000000000000000