INFO: task syz-executor:8578 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:20888 pid:8578 tgid:8578 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7048 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1312 task_work_run+0x1d4/0x260 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:44 [inline] exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb620790a77 RSP: 002b:00007fff2505c368 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fb620813d7d RCX: 00007fb620790a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff2505c420 RBP: 00007fff2505c420 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff2505d4b0 R13: 00007fb620813d7d R14: 0000000000049cf8 R15: 00007fff2505d4f0 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e13efa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5573: #0: ffff8880350720a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/6641: #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e594208 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by kworker/u8:23/7192: #0: ffff88801c736148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90003edfc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 2 locks held by syz-executor/8546: #0: ffff888056c020e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888056c020e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888056c020e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e594208 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/8578: #0: ffff888062c1a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888062c1a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888062c1a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e594208 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 1 lock held by syz.0.674/9611: #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.8.718/9813: #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88802de180e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz.6.791/10135: #0: ffff8880631180e0 (&type->s_umount_key#64/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xaa0 fs/super.c:344 #1: ffffffff8e594208 (jfs_log_mutex){+.+.}-{4:4}, at: open_dummy_log fs/jfs/jfs_logmgr.c:1191 [inline] #1: ffffffff8e594208 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogOpen+0x1a1/0xfa0 fs/jfs/jfs_logmgr.c:1066 6 locks held by kworker/0:18/10254: #0: ffff888140a81148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90003837c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff888029160198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888029160198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff888029163518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff888029163518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff888029163518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff888029163518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff888029163518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953 #4: ffff888144300168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff888144300168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff888144300168 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff888144300168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953 #5: ffffffff8edd3470 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14e/0x1850 drivers/usb/core/hub.c:3067 ============================================= 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 10/25/2025 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:161 [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:375 [inline] watchdog+0xe88/0xee0 kernel/hung_task.c:588 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 be 2a 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07dc0 EFLAGS: 000002c2 RAX: 00000000005d1d6d RBX: ffffffff8197161e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d9a0b7f RDI: ffffffff8be08c60 RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa25d70 R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f660ce8b001 CR3: 0000000075f6a000 CR4: 00000000003526f0 DR0: 0000000000800003 DR1: 00000000000001f5 DR2: 0000000000000483 DR3: 0000000000000007 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x386/0x3d0 init/main.c:1207 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147