INFO: task syz.3.3908:22855 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3908 state:D stack:27112 pid:22855 tgid:22852 ppid:21654 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2833 [inline] start_dirop fs/namei.c:2844 [inline] filename_create+0x1fb/0x360 fs/namei.c:4848 do_mkdirat+0xca/0x4b0 fs/namei.c:5125 __do_sys_mkdir fs/namei.c:5160 [inline] __se_sys_mkdir fs/namei.c:5158 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:5158 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d2638f749 RSP: 002b:00007f8d2721a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f8d265e6090 RCX: 00007f8d2638f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000020c0 RBP: 00007f8d26413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d265e6128 R14: 00007f8d265e6090 R15: 00007ffdeffcd6b8 INFO: task syz.3.3908:22858 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3908 state:D stack:26088 pid:22858 tgid:22852 ppid:21654 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1042 [inline] open_last_lookups fs/namei.c:4508 [inline] path_openat+0xab0/0x3d90 fs/namei.c:4753 do_filp_open+0x1fa/0x410 fs/namei.c:4783 do_sys_openat2+0x121/0x1c0 fs/open.c:1432 do_sys_open fs/open.c:1447 [inline] __do_sys_open fs/open.c:1455 [inline] __se_sys_open fs/open.c:1451 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1451 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d2638f749 RSP: 002b:00007f8d271f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f8d265e6180 RCX: 00007f8d2638f749 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000200000000100 RBP: 00007f8d26413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d265e6218 R14: 00007f8d265e6180 R15: 00007ffdeffcd6b8 INFO: task syz.3.3908:22860 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3908 state:D stack:28744 pid:22860 tgid:22852 ppid:21654 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2833 [inline] start_dirop fs/namei.c:2844 [inline] filename_create+0x1fb/0x360 fs/namei.c:4848 do_mkdirat+0xca/0x4b0 fs/namei.c:5125 __do_sys_mkdirat fs/namei.c:5155 [inline] __se_sys_mkdirat fs/namei.c:5153 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5153 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d2638de97 RSP: 002b:00007f8d271d7e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8d271d7ef0 RCX: 00007f8d2638de97 RDX: 00000000000001ff RSI: 0000200000000100 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100 R13: 00007f8d271d7eb0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by rcu_preempt/16: #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_change+0xd9/0x340 kernel/sched/psi.c:919 1 lock held by khungtaskd/31: #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5588: #0: ffff888034a920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:33/12921: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc900046cfb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by kworker/u8:12/19044: #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc900054ffb80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffffffff8f2cd9b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670 #3: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:13033 #4: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #4: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 3 locks held by syz.3.3908/22853: 2 locks held by syz.3.3908/22855: #0: ffff88805cc36420 (sb_writers#18){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509 #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2833 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2844 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4848 1 lock held by syz.3.3908/22858: #0: ffff88807739bdd8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff88807739bdd8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: open_last_lookups fs/namei.c:4508 [inline] #0: ffff88807739bdd8 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0xab0/0x3d90 fs/namei.c:4753 2 locks held by syz.3.3908/22860: #0: ffff88805cc36420 (sb_writers#18){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509 #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2833 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2844 [inline] #1: ffff88807739bdd8 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4848 7 locks held by syz-executor/24182: #0: ffff888033016420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888033016420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682 #1: ffff888063bf6888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343 #2: ffff888027afca58 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888027afca58 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344 #3: ffffffff8eb71548 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff88807c8990e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88807c8990e8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #5: ffff88807c89e250 (&devlink->lock_key#39){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2144 1 lock held by syz-executor/24335: #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 1 lock held by syz.9.4210/24393: #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 1 lock held by syz-executor/24395: #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 5 locks held by syz.8.4213/24409: #0: ffff88803159cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88803159cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715 #1: ffff88803159c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314 #2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline] #2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637 #3: ffff8880207f9b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763 #4: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfb5/0x1000 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3 Comm: pool_workqueue_ Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:within kernel/locking/lockdep.c:6298 [inline] RIP: 0010:__lockdep_free_key_range kernel/locking/lockdep.c:6404 [inline] RIP: 0010:lockdep_unregister_key+0x1b4/0x310 kernel/locking/lockdep.c:6609 Code: fd 00 10 00 00 74 5e 4e 8b 24 ed 90 18 ff 95 eb 0f 4c 89 ff 4c 89 e6 e8 5a 54 00 00 4d 8b 24 24 4d 85 e4 74 d6 49 8b 44 24 40 <48> 39 d8 0f 93 c1 48 39 e8 0f 92 c0 84 c1 75 d7 49 8b 84 24 b8 00 RSP: 0018:ffffc90000087bc0 EFLAGS: 00000086 RAX: ffffffff99b7c9e0 RBX: ffff8880563f0938 RCX: 0000000000025400 RDX: ffffffff933a13d8 RSI: 0000000000000004 RDI: 00000000000a0076 RBP: ffff8880563f0939 R08: 0000000000000000 R09: ffffffff81ac1278 R10: dffffc0000000000 R11: fffffbfff1efbd6f R12: ffffffff93214e00 R13: 00000000000009f7 R14: 0000000000000000 R15: ffffffff937a13f8 FS: 0000000000000000(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f970569f40 CR3: 000000000dd38000 CR4: 00000000003526f0 Call Trace: wq_unregister_lockdep kernel/workqueue.c:4846 [inline] pwq_release_workfn+0x6d5/0x870 kernel/workqueue.c:5142 kthread_worker_fn+0x4e9/0xb50 kernel/kthread.c:1005 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246