INFO: task syz-executor142:5828 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor142 state:D stack:27848 pid:5828 tgid:5828 ppid:5673 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 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: 0033:0x7f6cbe8a9a19 RSP: 002b:00007fff182b6758 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f6cbe8a9a19 RDX: 0000000000000006 RSI: 0000200000000300 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f6cbe915222 R09: 00007f6cbe915222 R10: 00007f6cbe915222 R11: 0000000000000246 R12: 00007f6cbe91547b R13: 0000000000000001 R14: 0000200000000003 R15: 0000000000000000 INFO: task syz-executor142:5829 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor142 state:D stack:27848 pid:5829 tgid:5829 ppid:5671 task_flags:0x400140 flags:0x00080802 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 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: 0033:0x7f6cbe8a9a19 RSP: 002b:00007fff182b6758 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f6cbe8a9a19 RDX: 0000000000000006 RSI: 0000200000000300 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f6cbe915222 R09: 00007f6cbe915222 R10: 00007f6cbe915222 R11: 0000000000000246 R12: 00007f6cbe91547b R13: 0000000000000001 R14: 0000200000000003 R15: 0000000000000000 INFO: task syz-executor142:5830 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor142 state:D stack:27224 pid:5830 tgid:5830 ppid:5670 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 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: 0033:0x7f6cbe8a9a19 RSP: 002b:00007fff182b6758 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f6cbe8a9a19 RDX: 0000000000000006 RSI: 0000200000000300 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f6cbe915222 R09: 00007f6cbe915222 R10: 00007f6cbe915222 R11: 0000000000000246 R12: 00007f6cbe91547b R13: 0000000000000001 R14: 0000200000000003 R15: 0000000000000000 INFO: task syz-executor142:5831 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor142 state:D stack:27272 pid:5831 tgid:5831 ppid:5668 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 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: 0033:0x7f6cbe8a9a19 RSP: 002b:00007fff182b6758 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f6cbe8a9a19 RDX: 0000000000000006 RSI: 0000200000000300 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f6cbe915222 R09: 00007f6cbe915222 R10: 00007f6cbe915222 R11: 0000000000000246 R12: 00007f6cbe91547b R13: 0000000000000001 R14: 0000200000000003 R15: 0000000000000000 Showing all locks held in the system: 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 getty/5366: #0: ffff8880379300a0 (&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 syz-executor142/5672: #0: ffff88807b79a0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807b79a0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807b79a0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff88807b79a0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8f072960 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz-executor142/5828: #0: ffff88807a0d6450 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #1: ffffffff8f072960 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 2 locks held by syz-executor142/5829: #0: ffff88807a31a450 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #1: ffffffff8f072960 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 2 locks held by syz-executor142/5830: #0: ffff88807a7d0450 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #1: ffffffff8f072960 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 2 locks held by syz-executor142/5831: #0: ffff88806c1a4450 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #1: ffffffff8f072960 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 46 8b 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 cf 0f 00 fb f4 3c 4a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197e00 EFLAGS: 00000242 RAX: 0000000000117467 RBX: ffff88801eac2540 RCX: ffffffff8bbbd2d5 RDX: 0000000000000000 RSI: ffffffff8e1a810c RDI: ffffffff8c402680 RBP: ffffed1003d584a8 R08: 0000000000000001 R09: ffffed10170a678d R10: ffff8880b8533c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123ed8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055aa06bfa168 CR3: 000000000e994000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158