INFO: task syz.9.4551:23968 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.4551 state:D stack:28728 pid:23968 tgid:23967 ppid:21004 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:293 [inline] __down_common+0x371/0x8b0 kernel/locking/semaphore.c:318 down+0x74/0xa0 kernel/locking/semaphore.c:100 console_lock+0x5b/0xa0 kernel/printk/printk.c:2896 class_console_lock_constructor include/linux/console.h:734 [inline] con_install+0x99/0x620 drivers/tty/vt/vt.c:3743 tty_driver_install_tty drivers/tty/tty_io.c:1268 [inline] tty_init_dev.part.0+0x9e/0x470 drivers/tty/tty_io.c:1380 tty_init_dev include/linux/err.h:78 [inline] tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] tty_open+0x953/0xe20 drivers/tty/tty_io.c:2093 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6ab/0x14d0 fs/open.c:996 vfs_open+0x82/0x3f0 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x19fa/0x2440 fs/namei.c:5000 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9013b5e90e RSP: 002b:00007f9014a47b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9014a486c0 RCX: 00007f9013b5e90e RDX: 0000000000000002 RSI: 00007f9014a47c00 RDI: ffffffffffffff9c RBP: 00007f9013c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9013e26038 R14: 00007f9013e25fa0 R15: 00007fff1b5b8108 Showing all locks held in the system: locks held by pool_workqueue_/3: 1, on CPU#0: #0: ffffffff8edf5ce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 locks held by khungtaskd/31: 1, last CPU#0: #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6793 locks held by kworker/u8:7/761: 3, last CPU#0: #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc900045afd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffff888077a48258 (&devlink->lock_key#13){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834 locks held by getty/5345: 2, on CPU#0: #0: ffff88803819b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 locks held by kworker/u8:10/7011: 2, on CPU#0: #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc9000334fd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 locks held by kworker/u8:11/7419: 2, last CPU#0: #0: ffff888033d17140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90003a87d08 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 locks held by kworker/u8:12/7420: 2, on CPU#0: #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90003a77d08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 locks held by kworker/u8:16/7703: 3, last CPU#0: #0: ffff88801d2d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc900034e7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffffffff90cabc68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677 locks held by syz.2.2821/17566: 1, last CPU#0: #0: ffff888038b0cab0 (&ima_iint_mutex_key[depth]#3){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319 locks held by kworker/u8:8/20404: 2, on CPU#0: #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90004b5fd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 locks held by syz.4.4321/23015: 6, last CPU#0: #0: ffff88804c1620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffff88804c162128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:939 [inline] #1: ffff88804c162128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:958 [inline] #1: ffff88804c162128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write.isra.0+0x24b/0x890 drivers/tty/tty_io.c:1054 #2: ffff88804c1622c8 (&tty->termios_rwsem){++++}-{4:4}, at: class_rwsem_read_constructor include/linux/rwsem.h:259 [inline] #2: ffff88804c1622c8 (&tty->termios_rwsem){++++}-{4:4}, at: n_tty_write+0x1b8/0x1160 drivers/tty/n_tty.c:2349 #3: ffffc90003316370 (&ldata->output_lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #3: ffffc90003316370 (&ldata->output_lock){+.+.}-{4:4}, at: process_output_block drivers/tty/n_tty.c:513 [inline] #3: ffffc90003316370 (&ldata->output_lock){+.+.}-{4:4}, at: n_tty_write+0x54c/0x1160 drivers/tty/n_tty.c:2366 #4: ffffffff8edd6040 (console_lock){+.+.}-{0:0}, at: class_console_lock_constructor include/linux/console.h:734 [inline] #4: ffffffff8edd6040 (console_lock){+.+.}-{0:0}, at: do_con_write+0x15b/0x4980 drivers/tty/vt/vt.c:3290 #5: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #5: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #5: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline] #5: ffffffff8edd60b8 (console_srcu){....}-{0:0}, at: console_flush_one_record+0xfd/0xf10 kernel/printk/printk.c:3246 locks held by syz.9.4551/23968: 2, on CPU#0: #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline] #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093 #1: ffff8880618c21b0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x39/0x470 drivers/tty/tty_io.c:1379 locks held by syz.7.4587/24092: 1, on CPU#0: #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline] #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093 locks held by syz.5.4589/24103: 1, on CPU#0: #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2010 [inline] #0: ffffffff8fba5f60 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x425/0xe20 drivers/tty/tty_io.c:2093 locks held by syz-executor/24343: 1, on CPU#0: #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #0: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4214 locks held by syz-executor/24410: 3, last CPU#0: #0: ffffffff90cabc68 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:579 #1: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1136 #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x25/0x1a0 kernel/bpf/core.c:749 locks held by modprobe/24474: 2, last CPU#0: #0: ffff88807886a9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff88807886a9f8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299 #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290 locks held by modprobe/24475: 1, last CPU#0: #0: ffff88803c946808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 locks held by syz-executor/24477: 2, last CPU#0: #0: ffff888093638088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290 locks held by modprobe/24478: 3, last CPU#0: #0: ffff88803c8da808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 #1: ffff88807886c378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:619 [inline] #1: ffff88807886c378 (&mm->mmap_lock){++++}-{4:4}, at: __vmf_anon_prepare+0xf2/0x250 mm/memory.c:3896 #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #2: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495 ============================================= NMI backtrace for cpu 0 CPU: 0 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 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:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245