INFO: task syz-executor:4304 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:21808 pid: 4304 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914 gfs2_gl_hash_clear+0x1ab/0x2f0 fs/gfs2/glock.c:2183 gfs2_put_super+0x769/0x7d0 fs/gfs2/super.c:624 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe83be56f17 RSP: 002b:00007fff268a6ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fe83bebf71f RCX: 00007fe83be56f17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff268a6f80 RBP: 00007fff268a6f80 R08: 00007fff268a7f80 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff268a8010 R13: 00007fe83bebf71f R14: 0000000000023aa8 R15: 00007fff268a8050 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3951: #0: ffff88802c69f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4304: #0: ffff88807a92c0e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz.1.208/4594: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4594 Comm: syz.1.208 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 f2 ac 29 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 f3 b0 6e fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc90004236f50 EFLAGS: 00000002 RAX: 1ffffffff2cbfd00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000020 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000846de0 R12: dffffc0000000000 R13: 1ffffffff2c63530 R14: ffffffff965fe860 R15: 0000000000000000 FS: 0000555575ae7500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f008871c000 CR3: 000000002b6da000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:116 [inline] wait_for_xmitr+0x4c/0x260 drivers/tty/serial/8250/8250_port.c:2069 serial8250_console_putchar+0x1a/0x50 drivers/tty/serial/8250/8250_port.c:3309 uart_console_write+0xaa/0x100 drivers/tty/serial/serial_core.c:1981 serial8250_console_write+0xc46/0x1000 drivers/tty/serial/8250/8250_port.c:3386 call_console_drivers kernel/printk/printk.c:-1 [inline] console_unlock+0xb9a/0x1120 kernel/printk/printk.c:2744 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xda/0x130 kernel/printk/printk.c:2299 __show_trace_log_lvl+0x44e/0x550 arch/x86/kernel/dumpstack.c:284 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 sysfs_warn_dup fs/sysfs/dir.c:30 [inline] sysfs_create_dir_ns+0x26a/0x290 fs/sysfs/dir.c:64 create_dir lib/kobject.c:89 [inline] kobject_add_internal+0x6e0/0xd90 lib/kobject.c:263 kobject_add_varg lib/kobject.c:398 [inline] kobject_init_and_add+0x128/0x190 lib/kobject.c:481 gfs2_sys_fs_add+0x24f/0x4b0 fs/gfs2/sys.c:727 gfs2_fill_super+0x120f/0x1f00 fs/gfs2/ops_fstype.c:1202 get_tree_bdev+0x3f1/0x610 fs/super.c:1325 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f1c632dbf4a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdfa39b588 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffdfa39b610 RCX: 00007f1c632dbf4a RDX: 00002000000002c0 RSI: 0000200000000100 RDI: 00007ffdfa39b5d0 RBP: 00002000000002c0 R08: 00007ffdfa39b610 R09: 0000000000008c9b R10: 0000000000008c9b R11: 0000000000000246 R12: 0000200000000100 R13: 00007ffdfa39b5d0 R14: 0000000000012760 R15: 0000200000000400