INFO: task syz.7.11127:9392 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.7.11127 state:D stack:27104 pid:9392 tgid:9390 ppid:7400 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 __mutex_lock_common kernel/locking/mutex.c:710 [inline] __mutex_lock+0x856/0x1420 kernel/locking/mutex.c:794 nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:786 [inline] __sock_sendmsg net/socket.c:801 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2650 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2704 __sys_sendmsg net/socket.c:2736 [inline] __do_sys_sendmsg net/socket.c:2741 [inline] __se_sys_sendmsg net/socket.c:2739 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb2079c799 RSP: 002b:00007feb216fe028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007feb20a15fa0 RCX: 00007feb2079c799 RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007feb20832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb20a16038 R14: 00007feb20a15fa0 R15: 00007fff38c0a868 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75d720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5596: #0: ffff8880330660a0 (&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.6.10926/8504: #0: ffffffff8fc44ac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea87960 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938 2 locks held by syz.7.11127/9392: #0: ffffffff8fc44ac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea87960 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728 1 lock held by syz-executor/10290: #0: ffffffff8e763968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e763968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 3 locks held by syz.3.12415/16676: 3 locks held by cmp/16742: ============================================= NMI backtrace for cpu 1 CPU: 1 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 02/12/2026 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+0x51e/0xb90 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: 14101 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:select_idle_sibling kernel/sched/fair.c:8129 [inline] RIP: 0010:select_task_rq_fair+0xc6b/0x43b0 kernel/sched/fair.c:8826 Code: db 74 2d 48 83 c3 08 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 5c 20 00 00 40 b5 01 83 3b 00 <0f> 85 a7 15 00 00 44 89 e7 48 8b 74 24 10 e8 62 72 fc ff 31 ed 84 RSP: 0018:ffffc90000007c60 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88801aec4d88 RCX: dffffc0000000000 RDX: 0000000000000008 RSI: ffffffff8e1b347b RDI: ffffffff8c287c00 RBP: 0000000000000001 R08: ffffffff901246f7 R09: 1ffffffff20248de R10: dffffc0000000000 R11: ffffffff8198d6a0 R12: 0000000000000000 R13: ffff888035e28000 R14: ffffffff8e1fb790 R15: ffffffff8e1fb790 FS: 000055558aed3500(0000) GS:ffff888125448000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5fa8606286 CR3: 000000003626e000 CR4: 00000000003526f0 Call Trace: select_task_rq kernel/sched/core.c:3574 [inline] try_to_wake_up+0x4db/0x1380 kernel/sched/core.c:4283 hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2190 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x435/0x8e0 kernel/time/hrtimer.c:2112 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 02 ff 20 00 fb eb 44 e8 fa fe 20 00 e8 d5 f2 0b 0a 4d 85 f6 74 94 e8 eb fe 20 00 fb 48 c7 c7 40 fb 74 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18 RSP: 0018:ffffc900070bf9c0 EFLAGS: 00000293 RAX: ffffffff81a54095 RBX: ffffffff81a53f0f RCX: ffff888031278000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e74fb40 RBP: ffffc900070bfa70 R08: ffffffff901246f7 R09: 1ffffffff20248de R10: dffffc0000000000 R11: fffffbfff20248df R12: 0000000000000000 R13: 0000000000000047 R14: 0000000000000200 R15: 1ffff92000e17f3c _printk+0xdd/0x130 kernel/printk/printk.c:2504 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_printk_level+0x1ae/0x2c0 fs/xfs/xfs_message.c:44 xfs_fs_put_super+0x55/0x160 fs/xfs/xfs_super.c:1223 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2284 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a63b9d9d7 Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffcb0683f88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f7a63c32050 RCX: 00007f7a63b9d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb0684040 RBP: 00007ffcb0684040 R08: 00007ffcb0685040 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcb06850d0 R13: 00007f7a63c32050 R14: 000000000010e3ed R15: 00007ffcb0685110