INFO: task kworker/u4:4:59 blocked for more than 147 seconds. Not tainted 6.6.102-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:23568 pid:59 ppid:2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 linkwatch_event+0xe/0x60 net/core/link_watch.c:286 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 INFO: task syz-executor:6952 blocked for more than 152 seconds. Not tainted 6.6.102-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22280 pid:6952 ppid:6947 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 rtnl_lock net/core/rtnetlink.c:78 [inline] rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2555 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1904 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0ecab90a7c RSP: 002b:00007ffc664f4e70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0ecb8e4620 RCX: 00007f0ecab90a7c RDX: 000000000000003c RSI: 00007f0ecb8e4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc664f4ec4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f0ecb8e4670 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kworker/0:0/8: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:2/42: #0: ffff88802cc9c538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802cc9c538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000b2fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000b2fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4701 3 locks held by kworker/u4:4/59: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 5 locks held by kworker/u4:8/3459: #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000c937d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000c937d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaec50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606 #3: ffff888019ad0250 (&devlink->lock_key#9){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:60 [inline] #3: ffff888019ad0250 (&devlink->lock_key#9){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xe1/0x340 net/devlink/core.c:285 #4: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3f/0x180 drivers/net/netdevsim/netdev.c:417 2 locks held by klogd/5148: 2 locks held by udevd/5159: 2 locks held by getty/5550: #0: ffff8880319f20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/0:4/5822: #0: ffff888017871d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000468fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000468fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x91/0xd70 net/wireless/reg.c:2463 2 locks held by kworker/1:4/5843: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000487fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000487fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 3 locks held by syz-executor/6207: #0: ffff8880772f8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline] #0: ffff8880772f8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709 #1: ffff8880772f80b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5259 #2: ffffffff8e129188 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1982 [inline] #2: ffffffff8e129188 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2539 5 locks held by syz-executor/6294: #0: ffff8880772fce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline] #0: ffff8880772fce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709 #1: ffff8880772fc0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5259 #2: ffffffff8e129188 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1982 [inline] #2: ffffffff8e129188 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2539 #3: ffff888078d48b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1762 #4: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #4: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz-executor/6865: #0: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 3 locks held by kworker/0:8/6903: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90003427d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90003427d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz-executor/6952: #0: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfbba48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 2 locks held by sed/7028: 2 locks held by syz-executor/7037: 3 locks held by syz-executor/7043: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7037 Comm: syz-executor Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:379 [inline] RIP: 0010:__rcu_read_lock+0xd/0x60 kernel/rcu/tree_plugin.h:402 Code: 0f 8c 54 fb ff ff 4c 89 f7 e8 7f 72 6c 00 e9 47 fb ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 53 65 48 8b 1d d3 59 93 7e <48> 81 c3 3c 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc RSP: 0018:ffffc90003fc7678 EFLAGS: 00000293 RAX: ffffffff8192b85a RBX: ffff88802424da00 RCX: ffff88802424da00 RDX: 0000000000000000 RSI: ffffffff8afc66a0 RDI: 00007fb300b8e7eb RBP: 0000000000000001 R08: ffff88802424da00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8a8000d0 R13: 1ffff920007f8f10 R14: 00007fb300b8e7eb R15: 1ffff920007f8eee FS: 0000555574315500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f46da3ed440 CR3: 0000000052d12000 CR4: 00000000003506f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:784 [inline] is_bpf_text_address+0x1f/0x2a0 kernel/bpf/core.c:741 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 vm_area_alloc_pages mm/vmalloc.c:3089 [inline] __vmalloc_area_node mm/vmalloc.c:3158 [inline] __vmalloc_node_range+0x96b/0x1320 mm/vmalloc.c:3339 vmalloc_user+0x74/0x80 mm/vmalloc.c:3493 kcov_ioctl+0x58/0x630 kernel/kcov.c:714 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb300b8e7eb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fff20af7420 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007fb300b8e7eb RDX: 0000000000080000 RSI: ffffffff80086301 RDI: 00000000000000d8 RBP: 00007fb300db6038 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000