INFO: task syz.5.3447:19826 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.3447 state:D stack:28904 pid:19826 tgid:19824 ppid:8852 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 io_init_wq_offload io_uring/tctx.c:22 [inline] io_uring_alloc_task_context+0xff/0x570 io_uring/tctx.c:85 __io_uring_add_tctx_node+0x33e/0x4e0 io_uring/tctx.c:111 __io_uring_add_tctx_node_from_submit+0x91/0x120 io_uring/tctx.c:154 io_uring_add_tctx_node io_uring/tctx.h:32 [inline] __do_sys_io_uring_enter io_uring/io_uring.c:3511 [inline] __se_sys_io_uring_enter+0x24fc/0x2b20 io_uring/io_uring.c:3455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fca6258f749 RSP: 002b:00007fca634ca038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fca627e6090 RCX: 00007fca6258f749 RDX: 000000000000f9d0 RSI: 0000000000002b93 RDI: 0000000000000009 RBP: 00007fca62613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fca627e6128 R14: 00007fca627e6090 R15: 00007fca6290fa28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5587: #0: ffff88814cffb0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:9/9593: #0: ffff8880b883a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffff8880b8924048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8e66a818 (pool_lock#2){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #2: ffffffff8e66a818 (pool_lock#2){-.-.}-{2:2}, at: free_obj_work+0x101/0x4a0 lib/debugobjects.c:498 3 locks held by kworker/1:1/15571: #0: ffff88801a055948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a055948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9001b9c7ba0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9001b9c7ba0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.2.3388/19631: 2 locks held by syz.2.3397/19656: #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.5.3447/19825: 1 lock held by syz.5.3447/19826: #0: ffff88807c3880a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_init_wq_offload io_uring/tctx.c:22 [inline] #0: ffff88807c3880a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_alloc_task_context+0xff/0x570 io_uring/tctx.c:85 1 lock held by syz.4.3455/19856: #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 3 locks held by kworker/u8:0/20097: #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000395fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000395fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by syz.6.3612/20500: #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 1 lock held by syz.1.3706/20854: #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2cc288 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 18407 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events purge_vmap_node RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5602 [inline] RIP: 0010:lock_is_held_type+0xd6/0x190 kernel/locking/lockdep.c:5940 Code: 49 ff c7 49 63 85 28 0b 00 00 48 83 c3 28 49 39 c7 7c d8 eb 11 48 c7 c7 b0 e4 e0 8d 4c 89 fe e8 60 60 7b f9 eb cb 31 db eb 1c <83> fd ff 74 12 31 c0 f6 43 22 03 0f 95 c0 31 db 39 c5 0f 94 c3 eb RSP: 0018:ffffc9001ab77630 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8880331bc800 RCX: 94f897b888acbe00 RDX: 0000000000000000 RSI: ffffffff8df3d6e0 RDI: ffff8880331bc800 RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff8230d202 R10: dffffc0000000000 R11: fffff94000489a3f R12: 0000000000000246 R13: ffff8880331bbc80 R14: ffffffff8df3d6e0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888126138000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcaa4564b8 CR3: 000000000dd38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lookup_page_ext mm/page_ext.c:254 [inline] page_ext_get+0x1b0/0x2f0 mm/page_ext.c:528 __reset_page_owner+0x28/0x1f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2901 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:495 apply_to_pte_range mm/memory.c:3143 [inline] apply_to_pmd_range mm/memory.c:3187 [inline] apply_to_pud_range mm/memory.c:3223 [inline] apply_to_p4d_range mm/memory.c:3259 [inline] __apply_to_page_range+0xb66/0x13d0 mm/memory.c:3295 kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:616 kasan_release_vmalloc_node mm/vmalloc.c:2255 [inline] purge_vmap_node+0x214/0x8f0 mm/vmalloc.c:2272 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog