INFO: task syz.1.3373:17696 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3373 state:D stack:26424 pid:17696 tgid:17695 ppid:16264 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 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_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026 netlink_dump+0x702/0xe10 net/netlink/af_netlink.c:2325 __netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440 genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075 genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline] genl_rcv_msg+0x5e8/0x7a0 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: 0033:0x7f38dfd9ce59 RSP: 002b:00007f38e0bab028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f38e0015fa0 RCX: 00007f38dfd9ce59 RDX: 0000000000004000 RSI: 0000200000000180 RDI: 0000000000000003 RBP: 00007f38dfe32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f38e0016038 R14: 00007f38e0015fa0 R15: 00007ffdd84c3b98 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5381: #0: ffff8880368670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz.2.2063/13007: #0: ffffffff8fe3fb28 (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 3 locks held by syz.1.3373/17696: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff888055efb6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #2: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494 2 locks held by syz.0.4697/22630: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728 2 locks held by syz-executor/23392: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 1 lock held by syz.5.4925/23481: #0: ffff88802bfee140 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802bfee140 (&dev->mutex){....}-{4:4}, at: nfc_unregister_rfkill+0x63/0x280 net/nfc/core.c:1166 2 locks held by syz.5.4925/23482: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 4 locks held by syz.5.4925/23485: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffff88802bfee140 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802bfee140 (&dev->mutex){....}-{4:4}, at: nfc_dev_up+0x3f/0x350 net/nfc/core.c:95 #3: ffff88807eda0348 (&ndev->req_lock){+.+.}-{4:4}, at: nci_open_device net/nfc/nci/core.c:478 [inline] #3: ffff88807eda0348 (&ndev->req_lock){+.+.}-{4:4}, at: nci_dev_up+0xa3/0xdd0 net/nfc/nci/core.c:643 2 locks held by syz.5.4925/23501: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 2 locks held by syz.4.4927/23493: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 2 locks held by syz.4.4927/23497: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 2 locks held by syz.3.4931/23519: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 2 locks held by syz.6.4939/23543: #0: ffffffff8fe3fb28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fe3f960 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 ============================================= 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 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+0x389/0x470 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: 23506 Comm: syz.5.4925 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_release+0x93/0x3c0 kernel/locking/lockdep.c:5885 Code: 0f 85 0d 02 00 00 65 4c 8b 3d 81 79 97 11 41 83 bf 8c 0b 00 00 00 0f 85 f7 01 00 00 49 81 3e 80 33 fd 93 0f 84 ea 01 00 00 9c <5b> fa 48 c7 c7 4e 0c fc 8d e8 df ea 06 0a 65 ff 05 f8 be 97 11 c7 RSP: 0018:ffffc900037775c8 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000086 RCX: 0000000080000004 RDX: 0000000000000001 RSI: ffffffff8c28af40 RDI: ffffffff8c28af00 RBP: ffffffff9a747410 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520006eeeb8 R12: ffff88813fe51d38 R13: ffffffff84bcb40c R14: ffffffff9a747430 R15: ffff88802ce35c40 FS: 00007f39fcc7d6c0(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff57cbea540 CR3: 000000005ba20000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:198 debug_object_assert_init+0x1dc/0x3b0 lib/debugobjects.c:1026 debug_hrtimer_assert_init kernel/time/hrtimer.c:495 [inline] hrtimer_start_range_ns+0x3f/0xed0 kernel/time/hrtimer.c:1477 hrtimer_start include/linux/hrtimer.h:220 [inline] hrtick_cond_restart kernel/sched/core.c:924 [inline] hrtick_schedule_exit kernel/sched/core.c:986 [inline] finish_lock_switch kernel/sched/core.c:5124 [inline] finish_task_switch+0x3cd/0xbe0 kernel/sched/core.c:5243 context_switch kernel/sched/core.c:5391 [inline] __schedule+0x1829/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 futex_do_wait kernel/futex/waitwake.c:358 [inline] __futex_wait+0x1ee/0x420 kernel/futex/waitwake.c:691 futex_wait+0x121/0x390 kernel/futex/waitwake.c:719 do_futex+0x333/0x420 kernel/futex/syscalls.c:130 __do_sys_futex kernel/futex/syscalls.c:207 [inline] __se_sys_futex+0x3a8/0x450 kernel/futex/syscalls.c:188 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: 0033:0x7f39fbd9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f39fcc7d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f39fc016278 RCX: 00007f39fbd9ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f39fc016278 RBP: 00007f39fc016270 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f39fc016308 R14: 00007ffedd93ad80 R15: 00007ffedd93ae68