INFO: task syz-executor:7049 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22184 pid:7049 tgid:7049 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5535 [inline] __schedule+0x1b47/0x5c60 kernel/sched/core.c:7305 __schedule_loop kernel/sched/core.c:7382 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7397 bit_wait+0x13/0x110 kernel/sched/wait_bit.c:248 __wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:78 [inline] gfs2_glock_wait+0xb3/0x2a0 fs/gfs2/glock.c:1239 gfs2_glock_nq_init fs/gfs2/glock.h:253 [inline] __gfs2_lookup+0x136/0x2b0 fs/gfs2/inode.c:1006 __lookup_slow+0x1fb/0x2f0 fs/namei.c:1919 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] lookup_last fs/namei.c:2789 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2813 filename_lookup+0x265/0x5d0 fs/namei.c:2842 user_path_at+0x40/0x160 fs/namei.c:3641 ksys_umount fs/namespace.c:2067 [inline] __do_sys_umount fs/namespace.c:2075 [inline] __se_sys_umount fs/namespace.c:2073 [inline] __x64_sys_umount+0xf6/0x170 fs/namespace.c:2073 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf1ed9f397 RSP: 002b:00007ffdb9549b18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fbf1ee344bb RCX: 00007fbf1ed9f397 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdb9549bd0 RBP: 00007ffdb9549bd0 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdb954acc0 R13: 00007fbf1ee344bb R14: 000000000006fbaa R15: 00007ffdb954ce80 Showing all locks held in the system: locks held by kworker/0:1/10: 4, last CPU#0: #0: ffff888035723148 ((wq_completion)wg-kex-wg0#18){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888035723148 ((wq_completion)wg-kex-wg0#18){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888035723148 ((wq_completion)wg-kex-wg0#18){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888035723148 ((wq_completion)wg-kex-wg0#18){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc900000f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc900000f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc900000f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc900000f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff888077e59440 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0x14e/0x9f0 drivers/net/wireguard/noise.c:678 #3: ffff888077ca7028 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0x15f/0x9f0 drivers/net/wireguard/noise.c:679 locks held by khungtaskd/34: 1, last CPU#1: #0: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by getty/5371: 2, on CPU#0: #0: ffff8880355c30a0 (&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 locks held by syz-executor/5611: 1, last CPU#1: #0: ffff888079966460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 locks held by kworker/1:7/5837: 5, on CPU#1: #0: ffff888023296d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888023296d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888023296d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888023296d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90005397c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90005397c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90005397c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90005397c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff888029fdc1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888029fdc1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917 #3: ffff88802a008568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3270 [inline] #3: ffff88802a008568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5482 [inline] #3: ffff88802a008568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #3: ffff88802a008568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #3: ffff88802a008568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5971 #4: ffff888029dd1a60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5483 [inline] #4: ffff888029dd1a60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #4: ffff888029dd1a60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #4: ffff888029dd1a60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5971 locks held by kworker/u8:16/6997: 2, on CPU#1: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc900033cfc40 (connector_reaper_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc900033cfc40 (connector_reaper_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc900033cfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc900033cfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 locks held by syz-executor/7049: 1, on CPU#1: #0: ffff88803a7c4100 (&type->i_mutex_dir_key#28 ){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] ){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 locks held by syz.3.1595/13460: 2, last CPU#0: #0: ffff88802f90e460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0xb41/0x10f0 fs/coredump.c:1306 #1: ffff888020f8bf78 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888020f8bf78 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3634 locks held by syz.5.1639/13558: 2, on CPU#0: #0: ffffffff902512a0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff902512a0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3587 #1: ffffffff8ed628e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8ed628e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2cb/0x760 kernel/rcu/tree_exp.h:966 locks held by syz.9.1640/13562: 1, last CPU#0: #0: ffffffff8eeaf8d0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:213 [inline] #0: ffffffff8eeaf8d0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:320 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline] watchdog+0x1058/0x10d0 kernel/hung_task.c:598 kthread+0x38b/0x480 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: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:432 Code: 45 50 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3c 36 c2 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 57 cb 75 06 cc 44 89 f9 80 e1 07 38 c1 RSP: 0018:ffffc90000157900 EFLAGS: 00000002 RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 00000000000003f8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff85788e00 R12: dffffc0000000000 R13: 000000000000005b R14: ffffffff9ad56f80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124db7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdb2c29f80 CR3: 0000000079ca2000 CR4: 00000000003526f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: serial_port_out include/linux/serial_core.h:817 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3302 [inline] __serial8250_console_fifo_write+0x1e6/0x3e0 drivers/tty/serial/8250/8250_port.c:3374 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3393 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3444 [inline] serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3508 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271 kthread+0x38b/0x480 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