INFO: task syz.4.1317:11418 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.4.1317 state:D stack:25768 pid:11418 tgid:11407 ppid:10477 task_flags:0x400548 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 io_wq_exit_workers io_uring/io-wq.c:1327 [inline] io_wq_put_and_exit+0x316/0x650 io_uring/io-wq.c:1355 io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:203 io_uring_cancel_generic+0x6ca/0x7d0 io_uring/io_uring.c:3340 io_uring_files_cancel include/linux/io_uring.h:19 [inline] do_exit+0x345/0x2300 kernel/exit.c:912 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6dc6b8efc9 RSP: 002b:00007f6dc7ab60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6dc6de6188 RCX: 00007f6dc6b8efc9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6dc6de6188 RBP: 00007f6dc6de6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6dc6de6218 R14: 00007ffc587dd560 R15: 00007ffc587dd648 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff8880b863a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffff8880b8624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by khungtaskd/31: #0: ffffffff8e13d720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: #0: ffff88813fe69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 4 locks held by kworker/1:1/43: 2 locks held by getty/5587: #0: ffff88803055d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:6/5917: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004617ba0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004617ba0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e1431b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8e1431b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 4 locks held by kworker/u8:13/9157: #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000d717ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000d717ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4d4c50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:670 #3: ffffffff8f4e1dc8 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1674 3 locks held by iou-wrk-11418/11419: 3 locks held by syz-executor/12420: #0: ffff888026f84dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff888026f84dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715 #1: ffff888026f840b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5303 #2: ffffffff8e1431b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e1431b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz-executor/13138: #0: ffffffff8f4e1dc8 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1e10 drivers/net/tun.c:3078 4 locks held by syz.6.1821/13221: #0: ffff888079a98dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff888079a98dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715 #1: ffff888079a980b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5303 #2: ffffffff8f64b1e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2132 [inline] #2: ffffffff8f64b1e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2625 #3: ffff888028382338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762 1 lock held by syz.8.1823/13224: #0: ffffffff8f4e1dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f4e1dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f4e1dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x346/0x700 net/core/rtnetlink.c:3555 1 lock held by syz.9.1826/13231: ============================================= 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 10/02/2025 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:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 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: 11419 Comm: iou-wrk-11418 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:native_read_msr_safe arch/x86/include/asm/msr.h:121 [inline] RIP: 0010:__rdmsr_safe_on_cpu+0x3c/0x130 arch/x86/lib/msr-smp.c:156 Code: bd 00 00 00 00 00 fc ff df e8 e0 3c f5 fc 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 82 00 00 00 44 8b 23 44 89 e1 0f 32 <31> ed 49 89 c7 49 89 d6 0f 1f 44 00 00 e8 b2 3c f5 fc 49 c1 e6 20 RSP: 0018:ffffc9000cb2f3c8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffc9000cb2f5a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8bc07cc0 RDI: ffffc9000cb2f5a0 RBP: ffffc9000cb2f4d8 R08: ffffffff8f9e3577 R09: 1ffffffff1f3c6ae R10: dffffc0000000000 R11: ffffffff84cb3a10 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff84cb3a10 R15: 1ffff92001965ead FS: 00007f6dc7ab66c0(0000) GS:ffff888125cfd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000cda000 CR3: 0000000027b5c000 CR4: 00000000003526f0 Call Trace: csd_do_func kernel/smp.c:136 [inline] generic_exec_single+0x23a/0x500 kernel/smp.c:439 smp_call_function_single_async+0x79/0x110 kernel/smp.c:732 rdmsr_safe_on_cpu+0x127/0x230 arch/x86/lib/msr-smp.c:179 msr_read+0x14d/0x250 arch/x86/kernel/msr.c:66 loop_rw_iter+0x425/0x660 include/linux/uio.h:-1 io_iter_do_read io_uring/rw.c:836 [inline] __io_read+0x1338/0x1500 io_uring/rw.c:951 io_read+0x4a/0x1c0 io_uring/rw.c:1031 __io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1837 io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1860 io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1972 io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:650 io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:704 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245