INFO: task syz-executor:7721 blocked for more than 144 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21640 pid:7721 tgid:7721 ppid:1 task_flags:0x40014c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:576 nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1364 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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x23c0 kernel/exit.c:976 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 __do_sys_exit_group kernel/exit.c:1129 [inline] __se_sys_exit_group kernel/exit.c:1127 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f5f5fb9c819 RSP: 002b:00007ffd8be59e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f5f5fc320ba RCX: 00007f5f5fb9c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000010 R08: 0000000000000000 R09: 00007f5f5fc32048 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8be5b130 R13: 00007f5f5fc32048 R14: 000055555a58d4e8 R15: 00007ffd8be5c200 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by khungtaskd/31: #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5575: #0: ffff8880365110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:10/6094: #0: ffff88801e38b148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801e38b148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004887c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004887c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 2 locks held by syz.0.278/7461: #0: ffffffff8fc3e630 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea86b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1903 1 lock held by dhcpcd/7489: #0: ffff88805a0207c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88805a0207c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88805a0207c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 2 locks held by syz-executor/7721: #0: ffff88807c0e20e0 (&type->s_umount_key#101){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807c0e20e0 (&type->s_umount_key#101){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807c0e20e0 (&type->s_umount_key#101){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ea86b48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:576 1 lock held by syz-executor/9417: 1 lock held by syz.6.774/9587: #0: ffff88807c0e20e0 (&type->s_umount_key#101){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88807c0e20e0 (&type->s_umount_key#101){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz.9.1106/11105: #0: ffff88807e335e08 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88807e335e08 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88807e335e08 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffff888065268260 (sk_lock-AF_CAIF){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline] #1: ffff888065268260 (sk_lock-AF_CAIF){+.+.}-{0:0}, at: caif_release+0xf9/0x380 net/caif/caif_socket.c:914 2 locks held by syz.5.1107/11110: #0: ffff88805a3ee3c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88805a3ee3c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88805a3ee3c8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffff88802a3ea260 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline] #1: ffff88802a3ea260 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x52/0x310 drivers/net/ppp/pptp.c:513 1 lock held by sed/11130: ============================================= 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 03/18/2026 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:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 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: 11122 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:312 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:850 [inline] RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1193 [inline] RIP: 0010:is_module_text_address+0x1d/0x1e0 kernel/module/main.c:3857 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 53 49 89 fe e8 ba 31 fc ff 48 8d 1d 00 00 00 00 <48> c7 c7 a0 e5 75 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 RSP: 0018:ffffc900035671e0 EFLAGS: 00000283 RAX: 0000000000000001 RBX: ffffffff81af50ad RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8c27d4e0 RDI: 00007fe4bcfe3636 RBP: 0000000000000001 R08: 0000000000000022 R09: ffffffff8e75e5a0 R10: dffffc0000000000 R11: ffffffff81b0dbf0 R12: ffff88802da60000 R13: ffff888029585a10 R14: 00007fe4bcfe3636 R15: 1ffff920006ace56 FS: 00007fe4bce49c80(0000) GS:ffff888125454000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe4bd0e57b8 CR3: 0000000011dec000 CR4: 0000000000350ef0 Call Trace: kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0x3e5/0x9f0 mm/rmap.c:342 anon_vma_fork+0x16a/0x570 mm/rmap.c:404 dup_mmap+0x991/0x1d90 mm/mmap.c:1804 dup_mm kernel/fork.c:1531 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1583 copy_process+0x18b6/0x3cd0 kernel/fork.c:2223 kernel_clone+0x248/0x8e0 kernel/fork.c:2653 __do_sys_clone kernel/fork.c:2794 [inline] __se_sys_clone kernel/fork.c:2778 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778 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: 0033:0x7fe4bcfe3636 Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffcb7e4b1d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffcb7e4b1d8 RCX: 00007fe4bcfe3636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000555cf63cac30 R08: 0000000000000000 R09: 0000000000000030 R10: 00007fe4bce49f50 R11: 0000000000000246 R12: 0000555cf63d8290 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000