INFO: task syz.4.5266:25232 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.4.5266 state:D stack:26200 pid:25232 tgid:25231 ppid:20801 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 super_lock+0x1c8/0x3b0 fs/super.c:115 __iterate_supers+0x126/0x290 fs/super.c:923 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x353/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec3fd8f749 RSP: 002b:00007fec40b93038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fec3ffe5fa0 RCX: 00007fec3fd8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fec3fe13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fec3ffe6038 R14: 00007fec3ffe5fa0 R15: 00007ffcebedfd18 INFO: task syz.4.5266:25235 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.4.5266 state:D stack:26312 pid:25235 tgid:25231 ppid:20801 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 super_lock+0x1c8/0x3b0 fs/super.c:115 __iterate_supers+0x126/0x290 fs/super.c:923 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x353/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec3fd8f749 RSP: 002b:00007fec40b72038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fec3ffe6090 RCX: 00007fec3fd8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102 RBP: 00007fec3fe13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fec3ffe6128 R14: 00007fec3ffe6090 R15: 00007ffcebedfd18 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5188: 7 locks held by kworker/1:3/5867: #0: ffff8880212ead48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000431fb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff888143b0d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888143b0d198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff888076e65198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888076e65198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #4: ffff888020af5160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888020af5160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #5: ffff888143b68518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #5: ffff888143b68518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_reset_device+0x549/0xb50 drivers/usb/core/hub.c:6409 #6: ffff888143722e68 (hcd->address0_mutex){+.+.}-{4:4}, at: usb_reset_and_verify_device+0x372/0x1ad0 drivers/usb/core/hub.c:6204 2 locks held by getty/6509: #0: ffff888034f4a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90004c7a2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 1 lock held by syz.6.5109/24287: #0: ffff88804297c0e0 (&type->s_umount_key#93/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xaa0 fs/super.c:344 3 locks held by syz.3.5951/28328: #0: ffffffff8eb91068 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8eb91068 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120 #1: ffff888058ade1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406 #2: ffffffff8e3331e0 (console_lock){+.+.}-{0:0}, at: class_console_lock_constructor include/linux/console.h:737 [inline] #2: ffffffff8e3331e0 (console_lock){+.+.}-{0:0}, at: con_install+0x9b/0x710 drivers/tty/vt/vt.c:3648 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 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+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:160 [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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: 28328 Comm: syz.3.5951 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:__bfs kernel/locking/lockdep.c:1815 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x197c/0x2cf0 kernel/locking/lockdep.c:5237 Code: 14 25 ff 0f 00 00 39 05 9e 3d 2d 12 73 06 89 05 96 3d 2d 12 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 b0 f3 20 RSP: 0018:ffffc90005257048 EFLAGS: 00000006 RAX: ffffffff965a50c8 RBX: 0000000000000111 RCX: 0000000000000002 RDX: ffffffff964f9bd8 RSI: ffff8880281d2a50 RDI: 0000000000000111 RBP: 57a62f5f3455fad0 R08: ffffc90005257010 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff819f1f10 R12: ffffc900052570d8 R13: ffffffff936d03e0 R14: ffff8880281d1e80 R15: 0000000000000001 FS: 00007f09961426c0(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0996141f98 CR3: 0000000058130000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline] pcpu_alloc+0x1d2/0x360 lib/debugobjects.c:281 alloc_object+0xbf/0x310 lib/debugobjects.c:458 lookup_object_or_alloc lib/debugobjects.c:685 [inline] __debug_object_init+0x102/0x4b0 lib/debugobjects.c:743 pm_runtime_init+0x17c/0x380 drivers/base/power/runtime.c:1856 device_pm_init drivers/base/power/power.h:169 [inline] device_initialize+0x24b/0x440 drivers/base/core.c:3165 device_create_groups_vargs drivers/base/core.c:4359 [inline] device_create+0x146/0x2f0 drivers/base/core.c:4410 vc_allocate+0x61b/0x6f0 drivers/tty/vt/vt.c:1104 con_install+0xa3/0x710 drivers/tty/vt/vt.c:3649 tty_driver_install_tty drivers/tty/tty_io.c:1295 [inline] tty_init_dev+0xd7/0x4d0 drivers/tty/tty_io.c:1407 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline] tty_open+0x5a6/0xd10 drivers/tty/tty_io.c:2120 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x785/0x14e0 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4627 [inline] path_openat+0x2de0/0x3840 fs/namei.c:4786 do_filp_open+0x1fa/0x410 fs/namei.c:4813 do_sys_openat2+0x121/0x200 fs/open.c:1391 do_sys_open fs/open.c:1397 [inline] __do_sys_openat fs/open.c:1413 [inline] __se_sys_openat fs/open.c:1408 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1408 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f099538df90 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 69 95 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 bc 95 02 00 8b 44 RSP: 002b:00007f0996141b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f099538df90 RDX: 0000000000000002 RSI: 00007f0996141c10 RDI: 00000000ffffff9c RBP: 00007f0996141c10 R08: 0000000000000000 R09: 00007f0996141986 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f09955e6128 R14: 00007f09955e6090 R15: 00007ffff20083e8