INFO: task syz.4.2579:11313 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.4.2579 state:D stack:27376 pid:11313 tgid:11310 ppid:5613 task_flags:0x400040 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+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fccf119e0d9 RSP: 002b:00007fccf2073028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fccf1425fa0 RCX: 00007fccf119e0d9 RDX: 0000000000004000 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007fccf1235024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fccf1426038 R14: 00007fccf1425fa0 R15: 00007ffc94ebd888 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b843b520 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:667 1 lock held by khungtaskd/30: #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by acpid/4968: #0: ffff88804cc50158 (&joydev->mutex){+.+.}-{4:4}, at: joydev_close_device drivers/input/joydev.c:220 [inline] #0: ffff88804cc50158 (&joydev->mutex){+.+.}-{4:4}, at: joydev_release+0x185/0x2a0 drivers/input/joydev.c:252 #1: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_close_device+0x46/0x280 drivers/input/input.c:646 2 locks held by getty/5367: #0: ffff888037df80a0 (&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 6 locks held by kworker/0:5/5742: #0: ffff888023ebdd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900046b7d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff88802b28c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #2: ffff88802b28c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4a60 drivers/usb/core/hub.c:5899 #3: ffff88802369d1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff88802369d1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff8880345201a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff8880345201a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff8880345201a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369 #5: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_disconnect_device drivers/input/input.c:703 [inline] #5: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: __input_unregister_device+0x24/0x4d0 drivers/input/input.c:2202 3 locks held by kworker/1:8/5821: #0: ffff88801bc0f140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9000533fd08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff8ebf3ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by udevd/6251: #0: ffff888022ad0110 (&evdev->mutex){+.+.}-{4:4}, at: evdev_close_device drivers/input/evdev.c:402 [inline] #0: ffff888022ad0110 (&evdev->mutex){+.+.}-{4:4}, at: evdev_release+0x29e/0x420 drivers/input/evdev.c:447 #1: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff88807dedc2b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_close_device+0x46/0x280 drivers/input/input.c:646 2 locks held by syz.0.2247/10551: #0: ffffffff90b4efe8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f072880 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 3 locks held by syz.4.2579/11313: #0: ffffffff90b4efe8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff888035ecc6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2410 #2: ffffffff8f072880 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb7/0x1200 fs/nfsd/nfsctl.c:1510 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 06 f3 5e 00 48 89 df 5b e9 1d 6e 64 00 be 03 00 00 00 5b e9 c2 37 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 45 1b 5a 12 48 8b 34 24 65 48 8b 15 21 1b 5a RSP: 0018:ffffc90000147bd8 EFLAGS: 00000097 RAX: 0000000000000000 RBX: 00000060cb63f894 RCX: ffffffff81fa8dbf RDX: 0000000000000003 RSI: 0000000000000004 RDI: ffff88801eaba540 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880b8423d80 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123dd8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe8ad5ed158 CR3: 0000000073331000 CR4: 00000000003526f0 Call Trace: tick_program_event+0x8e/0x140 kernel/time/tick-oneshot.c:48 hrtimer_rearm_event kernel/time/hrtimer.c:707 [inline] hrtimer_rearm kernel/time/hrtimer.c:2141 [inline] __hrtimer_rearm_deferred+0x234/0x720 kernel/time/hrtimer.c:2161 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] irqentry_exit+0x5f3/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 f6 d0 27 f6 48 89 df e8 7e 20 28 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 05 2e 17 f6 65 8b 05 4e 57 a6 08 85 c0 74 16 5b RSP: 0018:ffffc90000147d30 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b8428400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e1a826d RDI: ffffffff8c402680 RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8e80a100 R13: 0000000000000008 R14: 0000000000000100 R15: 0000000000000000 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1076 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1068 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160 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