INFO: task syz-executor:5843 blocked for more than 143 seconds. Not tainted 6.16.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:19880 pid:5843 tgid:5843 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 netfs_wait_for_outstanding_io include/linux/netfs.h:552 [inline] v9fs_evict_inode+0x170/0x320 fs/9p/vfs_inode.c:348 evict+0x501/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621 generic_shutdown_super+0x67/0x2c0 fs/super.c:621 kill_anon_super+0x3b/0x70 fs/super.c:1282 v9fs_kill_super+0x4c/0x90 fs/9p/vfs_super.c:193 deactivate_locked_super+0xbc/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: 0033:0x7f660e18ff17 RSP: 002b:00007ffd6cb2a4b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f660e18ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd6cb2a570 RBP: 00007ffd6cb2a570 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd6cb2b600 R13: 00007f660e211c05 R14: 000000000002b5d8 R15: 00007ffd6cb2b640 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5596: #0: ffff88814c1a70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5843: #0: ffff888057e140e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888057e140e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888057e140e0 (&type->s_umount_key#60){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 6 locks held by kworker/1:7/5925: #0: ffff888143e92d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888143e92d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000474fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000474fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888028647198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888028647198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff888028687510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888028687510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888028687510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888028687510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888028687510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20 drivers/usb/core/hub.c:5952 #4: ffff888143b66668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff888143b66668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff888143b66668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff888143b66668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20 drivers/usb/core/hub.c:5952 #5: ffffffff8edc8670 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x163/0x1750 drivers/usb/core/hub.c:3066 5 locks held by kworker/u8:12/6511: 1 lock held by syz.0.515/7946: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5925 Comm: kworker/1:7 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_switch+0x7/0x130 kernel/kcov.c:331 Code: 0a 20 e9 fc 37 a9 09 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 06 <48> 8b 4e 08 48 83 c1 f8 48 c1 c1 3d 48 83 f9 02 7f 1e 48 85 c9 74 RSP: 0018:ffffc9000474eac8 EFLAGS: 00000282 RAX: 0000000000000008 RBX: dffffc0000000000 RCX: 0000000000100000 RDX: 0000000000000000 RSI: ffffffff8f87bee0 RDI: 0000000000000000 RBP: ffffffff8b8b8921 R08: ffff888030a2da00 R09: 0000000000000002 R10: 0000000000000025 R11: 0000000000000002 R12: ffffc9000474ebc0 R13: ffffc9000474eda0 R14: 0000000000000000 R15: ffffffff8b8b8920 FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feadcd83ad8 CR3: 0000000029380000 CR4: 00000000003526f0 Call Trace: vsnprintf+0x118/0xf00 lib/vsprintf.c:2819 sprintf+0xd9/0x120 lib/vsprintf.c:3037 print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407 record_print_text+0x154/0x430 kernel/printk/printk.c:1456 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4917 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4928 _dev_info+0x10a/0x160 drivers/base/core.c:4986 hub_port_init+0x5cf/0x2800 drivers/usb/core/hub.c:4995 hub_port_connect drivers/usb/core/hub.c:5495 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2532/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245