INFO: task syz.5.285:5989 blocked for more than 148 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.285 state:D stack:28384 pid:5989 ppid:4878 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 d_wait_lookup fs/dcache.c:2634 [inline] d_alloc_parallel+0xb95/0x1530 fs/dcache.c:2716 __lookup_slow+0x113/0x3a0 fs/namei.c:1683 lookup_slow+0x53/0x70 fs/namei.c:1715 walk_component+0x2be/0x3f0 fs/namei.c:2006 lookup_last fs/namei.c:2463 [inline] path_lookupat+0x169/0x440 fs/namei.c:2487 filename_lookup+0x1f0/0x500 fs/namei.c:2516 user_path_at_empty+0x3e/0x60 fs/namei.c:2913 user_path_at include/linux/namei.h:57 [inline] do_mount fs/namespace.c:3418 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x297/0x3c0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd1c058f749 RSP: 002b:00007fd1c13d6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd1c07e6270 RCX: 00007fd1c058f749 RDX: 0000200000000180 RSI: 0000200000000140 RDI: 0000000000000000 RBP: 00007fd1c0613f91 R08: 0000200000000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1c07e6308 R14: 00007fd1c07e6270 R15: 00007ffd28669fa8 INFO: task syz.5.285:5992 blocked for more than 149 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.285 state:D stack:28384 pid:5992 ppid:4878 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 d_wait_lookup fs/dcache.c:2634 [inline] d_alloc_parallel+0xb95/0x1530 fs/dcache.c:2716 __lookup_slow+0x113/0x3a0 fs/namei.c:1683 lookup_slow+0x53/0x70 fs/namei.c:1715 walk_component+0x2be/0x3f0 fs/namei.c:2006 lookup_last fs/namei.c:2463 [inline] path_lookupat+0x169/0x440 fs/namei.c:2487 filename_lookup+0x1f0/0x500 fs/namei.c:2516 user_path_at_empty+0x3e/0x60 fs/namei.c:2913 user_path_at include/linux/namei.h:57 [inline] do_mount fs/namespace.c:3418 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x297/0x3c0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd1c058f749 RSP: 002b:00007fd1c13b5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd1c07e6360 RCX: 00007fd1c058f749 RDX: 0000200000000180 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007fd1c0613f91 R08: 0000200000000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1c07e63f8 R14: 00007fd1c07e6360 R15: 00007ffd28669fa8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (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: ffffffff8cb2be50 (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/28: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 5 locks held by kworker/u4:3/46: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b77d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffff8880437f13e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x112/0x300 drivers/net/wireguard/device.c:249 #4: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #4: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 2 locks held by getty/4029: #0: ffff88802f014098 (&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 2 locks held by kworker/u4:13/4550: 2 locks held by kworker/1:15/4769: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000c42fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 2 locks held by kworker/u4:15/4961: 1 lock held by dhcpcd/5517: #0: ffff888073eea010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff888073eea010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff888073eea010 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 1 lock held by syz.5.285/5986: 1 lock held by syz.5.285/5987: 1 lock held by syz.5.285/5989: #0: ffff8880727b06f0 (&type->i_mutex_dir_key#25){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880727b06f0 (&type->i_mutex_dir_key#25){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1714 1 lock held by syz.5.285/5992: #0: ffff8880727b06f0 (&type->i_mutex_dir_key#25){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] #0: ffff8880727b06f0 (&type->i_mutex_dir_key#25){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1714 3 locks held by kworker/1:19/6435: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900051ffd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 3 locks held by syz-executor/6505: #0: ffff88804d63d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88804d63d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff88804d63c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz-executor/6508: #0: ffff88801ffcd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88801ffcd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff88801ffcc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz-executor/6654: #0: ffff888058f550b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888058f550b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff888058f54078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz-executor/6688: #0: ffff88805c3750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88805c3750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff88805c374078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 2 locks held by kworker/1:21/6697: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900048dfd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by syz.6.364/6811: #0: ffff8880750690b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff8880750690b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff888075068078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz-executor/6826: #0: ffff888079b5d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888079b5d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff888079b5c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5228 #2: ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1820 [inline] ffffffff8de9f3c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 1 lock held by dhcpcd/6845: #0: ffff888072748210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff888072748210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff888072748210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 1 lock held by cmp/6856: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4452 Comm: kworker/u4:10 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_canary_byte mm/kfence/core.c:315 [inline] RIP: 0010:for_each_canary mm/kfence/core.c:345 [inline] RIP: 0010:kfence_guarded_free+0x296/0x780 mm/kfence/core.c:500 Code: 00 f0 ff ff 4c 89 ef 4c 89 fe e8 35 ba af ff 4d 39 fd 75 07 e8 4b b8 af ff eb 62 4c 89 ed 48 89 e8 48 c1 e8 03 42 0f b6 04 20 <84> c0 75 37 0f b6 45 00 41 89 ee 41 83 e6 07 41 31 c6 bf aa 00 00 RSP: 0018:ffffc900052ffa90 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffffffff96c90c68 RCX: ffff88802551bb80 RDX: 0000000000000000 RSI: 00000000000000aa RDI: 00000000000000aa RBP: ffff88823bdbc077 R08: dffffc0000000000 R09: fffffbfff2d95c56 R10: fffffbfff2d95c56 R11: 1ffffffff2d95c55 R12: dffffc0000000000 R13: ffff88823bdbc000 R14: 00000000000000aa R15: ffff88823bdbcf00 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc424b5eb4c CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_slab_free mm/slub.c:3641 [inline] slab_free mm/slub.c:3688 [inline] kmem_cache_free+0x199/0x290 mm/slub.c:3709 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x76b/0xaf0 drivers/net/netdevsim/dev.c:851 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