INFO: task syz.2.2373:15809 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2373 state:R running task stack:26480 pid:15809 tgid:15808 ppid:5637 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 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+0x7bf/0x1550 kernel/locking/mutex.c:821 exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 namespace_unlock+0x556/0x780 fs/namespace.c:1724 nsproxy_free kernel/nsproxy.c:66 [inline] deactivate_nsproxy+0x41/0x140 kernel/nsproxy.c:80 do_exit+0x735/0x2360 kernel/exit.c:1003 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f94b459de99 RSP: 002b:00007f94b548a028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 000000000000001c RBX: 00007f94b4825fa0 RCX: 00007f94b459de99 RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000008 RBP: 00007f94b4633eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f94b4826038 R14: 00007f94b4825fa0 R15: 00007ffcb25866a8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5375: #0: ffff888035eaf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:3/5732: #0: ffff88801b027140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b027140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000460fc40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000460fc40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 3 locks held by kworker/1:6/5780: #0: ffff8880b873b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667 #1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 #2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1a9/0xed0 kernel/time/timer.c:1085 2 locks held by kworker/u8:23/8381: #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9001aa37c40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9001aa37c40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 1 lock held by syz.4.1216/10870: 4 locks held by kworker/0:26/12142: #0: ffff88801b0d2d40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b0d2d40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004f9fc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004f9fc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8eb5ab48 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1813 [inline] #2: ffffffff8eb5ab48 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6c/0x16f0 kernel/rcu/srcutree.c:1973 #3: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.2.2373/15809: 1 lock held by syz.3.3221/19248: #0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline] #0: ffffffff9002c340 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3510 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5780 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Workqueue: events drain_vmap_area_work RIP: 0010:find_held_lock kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_release kernel/locking/lockdep.c:5535 [inline] RIP: 0010:lock_release+0x10c/0x3c0 kernel/locking/lockdep.c:5889 Code: 63 ec 48 89 04 24 83 f8 32 0f 83 2a 02 00 00 4a 8d 1c ad 00 00 00 00 4c 01 eb 48 8d 6c dd 00 48 89 ef 4c 89 f6 e8 24 a4 2c 0a <44> 89 64 24 14 45 89 e5 85 c0 0f 84 d7 00 00 00 48 85 ed 0f 84 13 RSP: 0018:ffffc900047ff378 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 000000000000000f RCX: 0000000000000046 RDX: ffffc900047ff401 RSI: ffffffff8eb59c60 RDI: ffff888026536918 RBP: ffff888026536918 R08: ffffc900047ff930 R09: 0000000000000000 R10: ffffc900047ff4d8 R11: fffff520008ffe9d R12: 0000000000000003 R13: 0000000000000003 R14: ffffffff8eb59c60 R15: ffff888026535d00 FS: 0000000000000000(0000) GS:ffff88812505e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555566d29a38 CR3: 0000000076c42000 CR4: 00000000003526f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3338 [inline] apply_to_pmd_range mm/memory.c:3382 [inline] apply_to_pud_range mm/memory.c:3418 [inline] apply_to_p4d_range mm/memory.c:3454 [inline] __apply_to_page_range+0xbd8/0x1420 mm/memory.c:3490 __kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2284 [inline] purge_vmap_node+0x220/0x960 mm/vmalloc.c:2306 __purge_vmap_area_lazy+0x783/0xb40 mm/vmalloc.c:2396 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 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