INFO: task syz-executor:4274 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:22144 pid:4274 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 folio_wait_bit_common+0x6e1/0xf60 mm/filemap.c:1324 truncate_inode_pages_range+0x9a2/0xff0 mm/truncate.c:422 evict+0x498/0x870 fs/inode.c:707 dispose_list fs/inode.c:738 [inline] evict_inodes+0x604/0x690 fs/inode.c:792 generic_shutdown_super+0x93/0x340 fs/super.c:480 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8274d8fed7 RSP: 002b:00007fff641edc28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8274e11c05 RCX: 00007f8274d8fed7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff641edce0 RBP: 00007fff641edce0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff641eed70 R13: 00007f8274e11c05 R14: 0000000000028666 R15: 00007fff641eedb0 Showing all locks held in the system: 3 locks held by kworker/u4:1/11: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4034: #0: ffff88814d2d3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4267: #0: ffff8880292340e0 (&type->s_umount_key#79){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 1 lock held by syz-executor/4272: #0: ffff8880298900e0 (&type->s_umount_key#79){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 1 lock held by syz-executor/4274: #0: ffff88805409c0e0 (&type->s_umount_key#79){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 2 locks held by kworker/u4:6/4349: #0: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x312/0x6d0 kernel/sched/psi.c:987 ============================================= 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 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4277 Comm: kworker/u5:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: hci6 hci_cmd_timeout RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 12 96 09 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 33 b7 59 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc90003df7438 EFLAGS: 00000002 RAX: 1ffffffff2dee000 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90003df7630 R08: dffffc0000000000 R09: ffffed1004850047 R10: ffffed1004850047 R11: 1ffff11004850046 R12: dffffc0000000000 R13: 0000000000002701 R14: ffffffff96f70480 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e9bfa4198 CR3: 000000007d0fa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:117 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:139 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2101 [inline] fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3366 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3388 [inline] serial8250_console_write+0xf26/0x17a0 drivers/tty/serial/8250/8250_port.c:3473 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 bt_err+0x108/0x150 net/bluetooth/lib.c:251 hci_cmd_timeout+0xd4/0x1e0 net/bluetooth/hci_core.c:1458 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295