INFO: task syz-executor:4199 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21456 pid: 4199 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914 gfs2_gl_hash_clear+0x1ab/0x2f0 fs/gfs2/glock.c:2183 gfs2_put_super+0x769/0x7d0 fs/gfs2/super.c:624 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f19ad67ff17 RSP: 002b:00007fffb9b2be08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f19ad6e871f RCX: 00007f19ad67ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffb9b2bec0 RBP: 00007fffb9b2bec0 R08: 00007fffb9b2cec0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffb9b2cf50 R13: 00007f19ad6e871f R14: 000000000000ff5c R15: 00007fffb9b2cf90 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:6/3112: 2 locks held by getty/3949: #0: ffff88814d3f3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4199: #0: ffff88807a3b20e0 (&type->s_umount_key#60){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 3 locks held by kworker/u5:5/4200: #0: ffff88807b915138 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002edfd00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff8880616ccff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open+0xa4/0x1270 net/bluetooth/hci_core.c:1446 3 locks held by kworker/0:18/8364: #0: ffff8880185be138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000387fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888024082220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #2: ffff888024082220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827 2 locks held by syz.7.1459/9221: #0: ffff888020003518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147b1c468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 1 lock held by dhcpcd-run-hook/9227: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7460 Comm: kworker/0:16 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events kfree_rcu_work RIP: 0010:unwind_next_frame+0x29/0x1d90 arch/x86/kernel/unwind_orc.c:424 Code: 90 55 41 57 41 56 41 55 41 54 53 48 81 ec 88 00 00 00 48 89 fb 49 be 00 00 00 00 00 fc ff df 48 8d 6f 48 48 89 e8 48 c1 e8 03 <48> 89 44 24 20 42 80 3c 30 00 74 08 48 89 ef e8 03 17 89 00 4c 8b RSP: 0018:ffffc9000340f628 EFLAGS: 00000a02 RAX: 1ffff92000681ee6 RBX: ffffc9000340f6e8 RCX: 0000000080000001 RDX: dffffc0000000000 RSI: ffffffff81bdfebb RDI: ffffc9000340f6e8 RBP: ffffc9000340f730 R08: ffffc9000340f7b0 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000681ee9 R12: ffff888077b23b80 R13: ffff888054543080 R14: dffffc0000000000 R15: ffffc9000340f6e8 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557797e28950 CR3: 000000002a378000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free_bulk+0x38b/0x490 mm/slub.c:3645 kfree_bulk include/linux/slab.h:465 [inline] kfree_rcu_work+0x2e3/0x7a0 kernel/rcu/tree.c:3299 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287