INFO: task syz-executor:5837 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:21960 pid:5837 tgid:5837 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: 0033:0x7fb140d8fc57 RSP: 002b:00007fffd1a48d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fb140e10925 RCX: 00007fb140d8fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd1a48de0 RBP: 00007fffd1a48de0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffd1a49ed0 R13: 00007fb140e10925 R14: 000000000002e741 R15: 00007fffd1a4c090 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 2 locks held by getty/5596: #0: ffff88814d4280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5837: #0: ffff88804bc0d188 (&type->i_mutex_dir_key#25){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:882 [inline] #0: ffff88804bc0d188 (&type->i_mutex_dir_key#25){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 5 locks held by kworker/1:7/5958: #0: ffff888020efc148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888020efc148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000b5e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b5e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff8880288ab198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff8880288ab198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5863 #3: ffff8880288ae510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff8880288ae510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline] #3: ffff8880288ae510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #3: ffff8880288ae510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #3: ffff8880288ae510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5917 #4: ffff8881443aef68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline] #4: ffff8881443aef68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #4: ffff8881443aef68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #4: ffff8881443aef68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5917 1 lock held by syz-executor/8411: #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by udevd/8910: 2 locks held by syz.0.674/9016: #0: ffff888029e6f4d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:11505 #1: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #1: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.0.674/9047: #0: ffffffff8f511d48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3038 #1: ffff888029e6f4d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_netdev_event+0xad/0x160 net/netfilter/nft_chain_filter.c:417 1 lock held by syz.0.674/9048: #0: ffffffff8f511d48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3038 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8411 Comm: syz-executor 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 RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1757 [inline] RIP: 0010:__hrtimer_run_queues+0x403/0xc60 kernel/time/hrtimer.c:1825 Code: 8d 74 24 28 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 2d 64 75 00 4d 8b 36 48 8b 7c 24 40 48 8b b4 24 a8 00 00 00 78 d9 ba 09 0f 1f 44 00 00 e8 2e ec 11 00 65 44 8b 2d 7a bd ee RSP: 0018:ffffc90000007d40 EFLAGS: 00000046 RAX: 1ffff92000859fad RBX: ffff8880b8627b88 RCX: ffff888034510000 RDX: 0000000000010000 RSI: 0000000000000806 RDI: ffff8880b8627ac0 RBP: ffffc90000007e90 R08: ffffffff8fa126f7 R09: 1ffffffff1f424de R10: dffffc0000000000 R11: fffffbfff1f424df R12: ffffc900042cfd40 R13: dffffc0000000000 R14: ffffffff81aeafb0 R15: 0000000000000001 FS: 0000555572b3a500(0000) GS:ffff888125c4d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7126df2b60 CR3: 0000000079640000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 71 61 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 60 61 1f 00 eb 06 e8 59 61 1f 00 fb 48 c7 c7 20 30 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 36 RSP: 0018:ffffc90005247940 EFLAGS: 00000293 RAX: ffffffff81a0fd87 RBX: ffffffff81a0fc44 RCX: ffff888034510000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e133020 RBP: ffffc90005247a50 R08: ffffffff8fa126f7 R09: 1ffffffff1f424de R10: dffffc0000000000 R11: fffffbfff1f424df R12: dffffc0000000000 R13: 1ffff92000a48f2c R14: 0000000000000200 R15: 000000000000005a _printk+0xcf/0x120 kernel/printk/printk.c:2475 _btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:248 btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_anon_super+0x3b/0x70 fs/super.c:1280 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2095 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f50d5b8fc57 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd4e244a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f50d5c10925 RCX: 00007f50d5b8fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd4e244b30 RBP: 00007ffd4e244b30 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd4e245bc0 R13: 00007f50d5c10925 R14: 0000000000053a41 R15: 00007ffd4e245c00