rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7808/1:b.el rcu: (detected by 0, t=10502 jiffies, g=27817, q=3343 ncpus=2) task:syz.4.499 state:R running task stack:23032 pid:7808 tgid:7802 ppid:5831 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__fib6_clean_all+0x32a/0x4b0 Code: b6 04 38 84 c0 75 6b 8b 44 24 2c 88 84 24 08 01 00 00 48 8d b4 24 a0 00 00 00 e8 81 27 00 00 4c 89 ef e8 69 18 5b 01 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 74 08 4c 89 e7 e8 13 c9 95 f7 4d 8b 24 RSP: 0018:ffffc9000419eba0 EFLAGS: 00000246 RAX: ffff88802923a000 RBX: ffffc9000419eca0 RCX: ffffffff817b275a RDX: dffffc0000000000 RSI: ffffffff8c0a96c0 RDI: ffffffff8c5faaa0 RBP: ffffc9000419ed30 R08: ffffffff942a188f R09: 1ffffffff2854311 R10: dffffc0000000000 R11: fffffbfff2854312 R12: ffff88802923a000 R13: ffff88802923a018 R14: ffffc9000419ec88 R15: dffffc0000000000 rt6_sync_down_dev net/ipv6/route.c:4908 [inline] rt6_disable_ip+0x170/0x800 net/ipv6/route.c:4913 addrconf_ifdown+0x15d/0x1bd0 net/ipv6/addrconf.c:3877 addrconf_notify+0x3cb/0x1020 notifier_call_chain+0x1a7/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] netdev_wait_allrefs_any net/core/dev.c:10790 [inline] netdev_run_todo+0x849/0x1000 net/core/dev.c:10905 rtnl_unlock net/core/rtnetlink.c:152 [inline] rtnl_net_unlock include/linux/rtnetlink.h:133 [inline] rtnl_dellink+0x760/0x8d0 net/core/rtnetlink.c:3526 rtnetlink_rcv_msg+0x793/0xcf0 net/core/rtnetlink.c:6921 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2542 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f8/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f94dc585d19 RSP: 002b:00007f94dd3f1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f94dc776080 RCX: 00007f94dc585d19 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007f94dc601a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f94dc776080 R15: 00007ffebfc524f8