INFO: task syz-executor:17341 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-executor state:D stack:21160 pid:17341 tgid:17341 ppid:1 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x165c/0x5560 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 __mutex_lock_common kernel/locking/mutex.c:710 [inline] __mutex_lock+0x856/0x1420 kernel/locking/mutex.c:794 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcfe8d9d9d7 RSP: 002b:00007ffd574595c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fcfe8e32050 RCX: 00007fcfe8d9d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd57459680 RBP: 00007ffd57459680 R08: 00007ffd5745a680 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd5745a710 R13: 00007fcfe8e32050 R14: 00000000000dd9c8 R15: 00007ffd5745a750 Showing all locks held in the system: 1 lock held by ksoftirqd/0/15: 1 lock held by khungtaskd/30: #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/0:2/808: 2 locks held by getty/5597: #0: ffff8880375640a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:7/8854: 4 locks held by kworker/u8:13/11007: #0: ffff8880b863ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #2: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #2: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #2: ffffffff8e75d7e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 #3: ffff8880b863ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 2 locks held by syz-executor/17341: #0: ffff88807d7ba0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807d7ba0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807d7ba0d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 3 locks held by kworker/1:1/17780: #0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3260 #1: ffffc900032e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3261 #2: ffff888065e54230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 2 locks held by syz.3.2095/17913: #0: ffff8880793dc0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880793dc0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880793dc0d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/18430: #0: ffff8880266c60d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880266c60d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880266c60d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz.6.2201/18741: #0: ffff888034d400d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888034d400d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888034d400d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/18829: #0: ffff888036f0e0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888036f0e0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888036f0e0d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz.8.2229/18904: #0: ffff888078bd40d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888078bd40d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888078bd40d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/18937: #0: ffff88807a7e00d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807a7e00d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807a7e00d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/18948: #0: ffff8880412720d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880412720d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880412720d8 (&type->s_umount_key#82){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ebf3040 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 1 lock held by syz.3.2385/19939: #0: ffff8880793dc0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880793dc0d8 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.6.2448/20644: #0: ffff888034d400d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888034d400d8 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/21202: 1 lock held by syz.8.2561/21450: #0: ffff888078bd40d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888078bd40d8 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.2565/21474: #0: ffff888036f0e0d8 (&type->s_umount_key#82){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.9.2566/21493: #0: ffffffff8e7638f8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 1 lock held by rm/21520: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 808 Comm: kworker/0:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:408 Code: ab 84 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 dc 11 ee fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 09 72 06 cc 44 89 f9 80 e1 07 38 c1 RSP: 0018:ffffc900047b6ff0 EFLAGS: 00000002 RAX: 000000000000006e RBX: 000000000000006e RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000022162 RDI: 0000000000022163 RBP: 00000000000003f8 R08: ffff888026328237 R09: 1ffff11004c65046 R10: dffffc0000000000 R11: ffffffff8541a590 R12: dffffc0000000000 R13: ffffffff9a2ce97b R14: ffffffff9a5e6de0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125448000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556c7094e8 CR3: 0000000076900000 CR4: 00000000003526f0 Call Trace: serial_port_out include/linux/serial_core.h:811 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3217 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x140c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 dev_vprintk_emit+0x355/0x420 drivers/base/core.c:4916 dev_printk_emit+0xee/0x140 drivers/base/core.c:4927 _dev_err+0x11e/0x180 drivers/base/core.c:4982 hub_port_init+0x1f5b/0x28d0 drivers/usb/core/hub.c:5171 hub_port_connect drivers/usb/core/hub.c:5496 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x2593/0x4f30 drivers/usb/core/hub.c:5953 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3288 process_scheduled_works kernel/workqueue.c:3379 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245