INFO: task syz-executor:5843 blocked for more than 143 seconds. Not tainted 6.15.0-next-20250606-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21080 pid:5843 tgid:5843 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:237 __wait_on_bit+0xb6/0x310 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1351 gfs2_glock_nq_init fs/gfs2/glock.h:238 [inline] __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:987 __lookup_slow+0x297/0x3d0 fs/namei.c:1817 lookup_slow+0x53/0x70 fs/namei.c:1834 walk_component+0x2d2/0x400 fs/namei.c:2138 lookup_last fs/namei.c:2639 [inline] path_lookupat+0x163/0x430 fs/namei.c:2663 filename_lookup+0x212/0x570 fs/namei.c:2692 user_path_at+0x3a/0x60 fs/namei.c:3127 ksys_umount fs/namespace.c:2147 [inline] __do_sys_umount fs/namespace.c:2155 [inline] __se_sys_umount fs/namespace.c:2153 [inline] __x64_sys_umount+0xee/0x160 fs/namespace.c:2153 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc8d838fc57 RSP: 002b:00007ffe63ff93c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fc8d8410925 RCX: 00007fc8d838fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe63ff9480 RBP: 00007ffe63ff9480 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe63ffa570 R13: 00007fc8d8410925 R14: 0000000000053aee R15: 00007ffe63ffc730 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 6 locks held by kworker/1:1/43: 2 locks held by getty/5594: #0: ffff888030a6c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5843: #0: ffff888053115ee8 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:882 [inline] #0: ffff888053115ee8 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 1 lock held by syz.4.1145/11560: 1 lock held by syz.7.1147/11561: #0: ffff88807cfd57e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:374 [inline] #0: ffff88807cfd57e0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1bd/0x4c0 mm/util.c:577 2 locks held by syz.7.1147/11562: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 43 Comm: kworker/1:1 Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:delay_tsc+0x5b/0xc0 arch/x86/lib/delay.c:79 Code: 90 49 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 02 31 2b f6 65 8b 05 fb 89 37 07 85 c0 74 1c f3 90 01 00 00 00 e8 3b 2f 2b f6 e8 f6 3b 01 00 39 c5 75 0e 0f 01 f9 RSP: 0018:ffffc90000b36d90 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000899 RCX: 0000000000000000 RDX: 00000000000000fe RSI: ffffffff8be2a860 RDI: 00000000ffffffff RBP: 0000000000000001 R08: ffff8880241d0237 R09: 1ffff1100483a046 R10: dffffc0000000000 R11: ffffffff8b65a5e0 R12: 1ffffffff33b9b3a R13: 00000000ffffffff R14: 000000fefacece9f R15: 0000000000000023 FS: 0000000000000000(0000) GS:ffff888125d4d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8557d80ab8 CR3: 0000000077bca000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2100 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4917 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4928 _dev_notice+0x10a/0x160 drivers/base/core.c:4985 usb_get_bos_descriptor+0x746/0x950 drivers/usb/core/config.c:1044 hub_port_init+0x17a0/0x2800 drivers/usb/core/hub.c:5175 hub_port_connect drivers/usb/core/hub.c:5464 [inline] hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] port_event drivers/usb/core/hub.c:5835 [inline] hub_event+0x2518/0x4a00 drivers/usb/core/hub.c:5917 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245