INFO: task syz.2.1827:12536 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1827 state:D stack:28680 pid:12536 tgid:12531 ppid:5819 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 bdev_release+0x15a/0x6d0 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:684 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 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+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee7138e929 RSP: 002b:00007fee72187038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fee715b5fa0 RCX: 00007fee7138e929 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fee71410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fee715b5fa0 R15: 00007ffefb25a5a8 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b843bc98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #0: ffff8880b843bc98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 1 lock held by khungtaskd/31: #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 5 locks held by kworker/1:1/42: #0: ffff888020efa148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000b27d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888144361198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888144361198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5863 #3: ffff888144364510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888144364510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline] #3: ffff888144364510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #3: ffff888144364510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #3: ffff888144364510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5917 #4: ffff888029118768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline] #4: ffff888029118768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #4: ffff888029118768 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #4: ffff888029118768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5917 3 locks held by kworker/1:2/2149: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90005897d10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff8e5cfe78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 2 locks held by getty/5585: #0: ffff88814c4f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5822: #0: ffffffff9034d228 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff9034d228 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396 1 lock held by udevd/5836: #0: ffff88802666f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.2.1827/12536: #0: ffff88802666f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1128 4 locks held by syz-executor/12719: #0: ffff888025bccd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:481 #1: ffff888025bcc078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5238 #2: ffffffff905be908 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2066 [inline] #2: ffffffff905be908 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2560 #3: ffff888073e37b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 1 lock held by syz.4.2453/14474: #0: ffffffff8e5cfe78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by syz.3.2458/14485: #0: ffff88805b6640e0 (&type->s_umount_key#68){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805b6640e0 (&type->s_umount_key#68){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805b6640e0 (&type->s_umount_key#68){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88805b6640e0 (&type->s_umount_key#68){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 14485 Comm: syz.3.2458 Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:get_reg arch/x86/kernel/unwind_orc.c:452 [inline] RIP: 0010:unwind_next_frame+0xdda/0x20a0 arch/x86/kernel/unwind_orc.c:643 Code: 84 96 07 00 00 3c 04 0f 84 b6 06 00 00 84 c0 0f 85 d4 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 <0f> 85 ac 10 00 00 49 8b 45 50 48 85 c0 74 5c 45 84 ff 75 28 48 b8 RSP: 0018:ffffc900034476a8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff9136834a RDX: 1ffff92000688eed RSI: 0000000000000006 RDI: ffffc90003447770 RBP: ffffc90003447760 R08: ffffffff9136834e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90003447768 R13: ffffc90003447718 R14: ffffc90003447f58 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124753000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000007000 CR3: 000000002aa87000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 vfree+0x1fd/0xb50 mm/vmalloc.c:3426 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x864/0x2bd0 kernel/exit.c:955 do_group_exit+0xd3/0x2a0 kernel/exit.c:1104 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 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+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa9be98e929 Code: Unable to access opcode bytes at 0x7fa9be98e8ff. RSP: 002b:00007fff6eea3cc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 00000000000d7d63 RCX: 00007fa9be98e929 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa9bebb608c RBP: 0000000000000bea R08: 00007fa9bf7c6000 R09: 000000156eea3fbf R10: 00007fff6eea3dc0 R11: 0000000000000246 R12: 00007fa9bebb608c R13: 00007fff6eea3dc0 R14: 00000000000d894d R15: 00007fff6eea3de0 vkms_vblank_simulate: vblank timer overrun