INFO: task syz.3.73:6198 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.73 state:D stack:25288 pid:6198 tgid:6197 ppid:5835 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 rcu_barrier+0x463/0x570 kernel/rcu/tree.c:3883 netdev_run_todo+0x327/0xea0 net/core/dev.c:11477 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline] ops_undo_list+0x3e1/0x990 net/core/net_namespace.c:247 setup_net+0x2d3/0x320 net/core/net_namespace.c:453 copy_net_ns+0x31b/0x4d0 net/core/net_namespace.c:570 create_new_namespaces+0x3f3/0x720 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:218 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3127 __do_sys_unshare kernel/fork.c:3198 [inline] __se_sys_unshare kernel/fork.c:3196 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3196 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f72de2bebe9 RSP: 002b:00007f72dc526038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f72de4f5fa0 RCX: 00007f72de2bebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f72de341e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f72de4f6038 R14: 00007f72de4f5fa0 R15: 00007ffe4548e3f8 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88801eb6c138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801eb6c138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000117bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000117bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 9 locks held by rcuc/1/28: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/67: #0: ffff88801f6df938 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801f6df938 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000152fbc0 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000152fbc0 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff88803b668750 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1551 6 locks held by kworker/u8:6/159: 3 locks held by kworker/u8:8/1451: #0: ffff888030283138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888030283138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000557fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000557fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 2 locks held by getty/5597: #0: ffff88823bf688a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 4 locks held by kworker/u9:2/5836: #0: ffff88807de5c138 ((wq_completion)hci16#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88807de5c138 ((wq_completion)hci16#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004ccfbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004ccfbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff88807da480a8 (&hdev->lock){+.+.}-{4:4}, at: le_conn_complete_evt+0xb1/0x1220 net/bluetooth/hci_event.c:5630 #3: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm+0x2c/0x140 include/net/bluetooth/hci_core.h:2079 1 lock held by syz-executor/5838: #0: ffffffff8d9ae570 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 4 locks held by kworker/u9:3/5839: #0: ffff888081a88938 ((wq_completion)hci14#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888081a88938 ((wq_completion)hci14#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004cefbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004cefbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880729700a8 (&hdev->lock){+.+.}-{4:4}, at: le_conn_complete_evt+0xb1/0x1220 net/bluetooth/hci_event.c:5630 #3: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm+0x2c/0x140 include/net/bluetooth/hci_core.h:2079 1 lock held by syz-executor/5841: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3433 4 locks held by kworker/1:3/5846: #0: ffff888019899938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019899938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004d4fbc0 ((work_completion)(&(&tbl->gc_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004d4fbc0 ((work_completion)(&(&tbl->gc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8d84a7a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163 #3: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: __local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168 4 locks held by kworker/u9:4/5848: #0: ffff88805e9b1938 ((wq_completion)hci8#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88805e9b1938 ((wq_completion)hci8#3){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004d7fbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004d7fbc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880721e00a8 (&hdev->lock){+.+.}-{4:4}, at: hci_remote_features_evt+0x9b/0x8e0 net/bluetooth/hci_event.c:3684 #3: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2079 [inline] #3: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_remote_features_evt+0x516/0x8e0 net/bluetooth/hci_event.c:3718 3 locks held by kworker/0:3/5876: #0: ffff888140adb938 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888140adb938 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004f7fbc0 ((work_completion)(&work->work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004f7fbc0 ((work_completion)(&work->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x151/0x7b0 drivers/infiniband/core/verbs.c:1995 3 locks held by kworker/u8:14/5998: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000545fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000545fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by kworker/u8:17/6195: 2 locks held by syz.3.73/6198: #0: ffffffff8ecc5a20 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8d9ae570 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 2 locks held by syz-executor/6239: #0: ffffffff8ecc5a20 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x79/0x270 net/mpls/af_mpls.c:2706 1 lock held by syz.2.89/6241: #0: ffffffff8d9ae570 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 1 lock held by syz.4.90/6250: #0: ffffffff8d9ae570 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 4 locks held by syz-executor/6256: #0: ffff88805cfd0e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88805cfd0e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715 #1: ffff88805cfd00a8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282 #2: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2599 #3: ffff888036d8eb58 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762 2 locks held by kworker/1:14/6262: 3 locks held by syz-executor/6263: #0: ffff88805f6f4e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88805f6f4e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715 #1: ffff88805f6f40a8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282 #2: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2599 6 locks held by kworker/1:15/6267: 2 locks held by syz-executor/6272: #0: ffff888033620e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff888033620e80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715 #1: ffff8880336200a8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282 4 locks held by kworker/u9:5/6273: #0: ffff88803cacc938 ((wq_completion)hci15#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88803cacc938 ((wq_completion)hci15#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90006377bc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90006377bc0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff88807e95c0a8 (&hdev->lock){+.+.}-{4:4}, at: le_conn_complete_evt+0xb1/0x1220 net/bluetooth/hci_event.c:5630 #3: ffffffff8ee3a2b8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm+0x2c/0x140 include/net/bluetooth/hci_core.h:2079 1 lock held by syz-executor/6328: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/6334: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/6339: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/6342: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/6345: #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by dhcpcd/6354: #0: ffff88805d5eaaf8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805d5eaaf8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88805d5eaaf8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by dhcpcd/6355: #0: ffff88805d5e8ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805d5e8ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88805d5e8ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by dhcpcd/6356: #0: ffff88805d606e78 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805d606e78 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88805d606e78 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by dhcpcd/6357: #0: ffff88805d605a38 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805d605a38 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88805d605a38 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by dhcpcd/6358: #0: ffff88805d6045f8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805d6045f8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88805d6045f8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by dhcpcd/6360: #0: ffff888088038350 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff888088038350 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3251 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: 28 Comm: rcuc/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:869 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1155 [inline] RIP: 0010:unwind_next_frame+0x195c/0x2390 arch/x86/kernel/unwind_orc.c:680 Code: 00 00 c6 03 01 4c 8b 7c 24 48 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 2d 03 00 00 41 c7 06 00 00 00 00 31 db e8 84 be 83 09 <85> c0 74 3a e8 7b 3d 32 00 84 c0 75 31 e8 72 be 83 09 85 c0 74 28 RSP: 0000:ffffc90000a2e238 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff8fa73701 RCX: ffff88801caf0000 RDX: ffffc90000a2e301 RSI: dffffc0000000000 RDI: ffffc90000a2e310 RBP: dffffc0000000000 R08: ffffc90000a2fa30 R09: 0000000000000000 R10: ffffc90000a2e358 R11: fffff52000145c6d R12: ffffc90000a2fa40 R13: ffffc90000a28000 R14: ffffc90000a2e308 R15: ffffffff8172b165 FS: 0000000000000000(0000) GS:ffff8881269c1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfc89d4f98 CR3: 000000000d7a6000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x143/0x310 mm/slub.c:4236 dst_alloc+0x105/0x170 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1645 [inline] __mkroute_output net/ipv4/route.c:2649 [inline] ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2870 ip_route_output_key_hash+0x1b9/0x2e0 net/ipv4/route.c:2700 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x6d2/0x1030 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x359/0x6c0 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8bb/0xe20 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:5991 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6104 process_backlog+0x31e/0x900 net/core/dev.c:6456 __napi_poll+0xb3/0x540 net/core/dev.c:7506 napi_poll net/core/dev.c:7569 [inline] net_rx_action+0x707/0xe00 net/core/dev.c:7696 handle_softirqs+0x22f/0x710 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] __local_bh_enable_ip+0x179/0x270 kernel/softirq.c:259 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch kernel/rcu/tree.c:2624 [inline] rcu_core kernel/rcu/tree.c:2861 [inline] rcu_cpu_kthread+0xc3d/0x1b50 kernel/rcu/tree.c:2949 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245