INFO: task kworker/u8:1:13 blocked for more than 143 seconds. Not tainted 6.16.0-syzkaller-12256-g561c80369df0 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:24408 pid:13 tgid:13 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __debugfs_file_removed fs/debugfs/inode.c:760 [inline] remove_one+0x312/0x420 fs/debugfs/inode.c:767 __simple_recursive_removal+0x158/0x610 fs/libfs.c:631 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:790 nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227 nsim_dev_reload_destroy+0x144/0x4d0 drivers/net/netdevsim/dev.c:1710 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:983 devlink_reload+0x19e/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:160 [inline] ops_undo_list+0x184/0xab0 net/core/net_namespace.c:233 cleanup_net+0x408/0x890 net/core/net_namespace.c:682 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.4.1032:10826 blocked for more than 144 seconds. Not tainted 6.16.0-syzkaller-12256-g561c80369df0 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1032 state:D stack:27352 pid:10826 tgid:10825 ppid:10613 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x82a/0x10b0 kernel/locking/mutex.c:760 devlink_health_report+0x3ba/0x9c0 net/devlink/health.c:627 nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162 full_proxy_write+0x12e/0x1a0 fs/debugfs/file.c:388 vfs_write+0x29d/0x11d0 fs/read_write.c:684 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fac5ef8ebe9 RSP: 002b:00007fac5fd15038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fac5f1b5fa0 RCX: 00007fac5ef8ebe9 RDX: 00000000000001ff RSI: 0000200000005900 RDI: 0000000000000004 RBP: 00007fac5f011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac5f1b6038 R14: 00007fac5f1b5fa0 R15: 00007ffcdac1d9a8 Showing all locks held in the system: 6 locks held by kworker/u8:1/13: #0: ffff88801c6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000127d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff9036f2f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658 #3: ffff88805fb030e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff88805fb030e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88805fb030e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff88805fb04250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff88805fb04250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff88805fb04250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffff88805f42a4f0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #5: ffff88805f42a4f0 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: __simple_recursive_removal+0x354/0x610 fs/libfs.c:627 1 lock held by khungtaskd/31: #0: ffffffff8e5c0fe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c0fe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c0fe0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by kworker/u9:1/5185: #0: ffff88802685e148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000ec17d10 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u9:2/5864: #0: ffff8880267b4948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003f5fd10 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 3 locks held by kworker/1:3/10457: #0: ffff88801b880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9001897fd10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e5cc578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by getty/10605: #0: ffff88814d2cd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900033a32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz.4.1032/10826: #0: ffff8880315fdb38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232 #1: ffff8881404e4428 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff88805fb04250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_health_report+0x3ba/0x9c0 net/devlink/health.c:627 1 lock held by syz.0.1406/12658: #0: ffffffff90385548 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90385548 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 1 lock held by syz.1.1414/12659: 1 lock held by syz.1.1427/12734: #0: ffffffff90385548 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90385548 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 4 locks held by syz.5.1421/12745: #0: ffff888028590dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff8880285900b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905ed528 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2062 [inline] #2: ffffffff905ed528 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2564 #3: ffff888079aaf338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller-12256-g561c80369df0 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 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: 12659 Comm: syz.1.1414 Not tainted 6.16.0-syzkaller-12256-g561c80369df0 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:451 [inline] RIP: 0010:__lock_acquire+0x689/0x1ce0 kernel/locking/lockdep.c:5225 Code: c6 01 c8 c1 c2 06 41 31 d6 44 89 f2 44 29 f1 41 01 c6 c1 c2 08 31 d1 89 ca 29 c8 44 01 f1 c1 c2 10 89 cf 31 d0 89 c6 41 29 c6 <01> c8 c1 ce 0d 44 31 f6 89 f2 29 f7 01 f0 c1 c2 04 89 c0 31 fa 48 RSP: 0018:ffffc9000bdef098 EFLAGS: 00000006 RAX: 00000000a5aae650 RBX: ffff888030eec6f0 RCX: 00000000ef9d33e4 RDX: 00000000b5f8efad RSI: 00000000a5aae650 RDI: 00000000ef9d33e4 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888030eec6f0 R13: ffff888030eebc00 R14: 000000005a44979c R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881247c6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000092000 CR3: 0000000077d58000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] __page_table_check_zero+0x13d/0x5d0 mm/page_table_check.c:138 page_table_check_free include/linux/page_table_check.h:43 [inline] free_pages_prepare mm/page_alloc.c:1396 [inline] free_unref_folios+0xa52/0x16b0 mm/page_alloc.c:2952 folios_put_refs+0x56f/0x740 mm/swap.c:997 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1150 mm/shmem.c:1157 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1397 evict+0x3e3/0x920 fs/inode.c:810 iput_final fs/inode.c:1897 [inline] iput fs/inode.c:1923 [inline] iput+0x521/0x880 fs/inode.c:1909 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466 __dentry_kill+0x1d0/0x600 fs/dcache.c:669 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911 dput+0x1f/0x30 fs/dcache.c:901 __fput+0x51c/0xb70 fs/file_table.c:476 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:73 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x41e000 Code: Unable to access opcode bytes at 0x41dfd6. RSP: 002b:000000000000000a EFLAGS: 00010206 RAX: 0000000000000000 RBX: 00007fda5f3b6180 RCX: 00007fda5f18ebe9 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46 RBP: 00007fda5f211e19 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fda5f3b6218 R14: 00007fda5f3b6180 R15: 00007ffc1eb45468