rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4028/1:b..l (detected by 1, t=10502 jiffies, g=4941, q=44) task:syz-executor188 state:R running task stack: 0 pid: 4028 ppid: 4023 flags:0x00000004 Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xe00/0x1c0c kernel/sched/core.c:6376 preempt_schedule_common+0x138/0x218 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 vprintk_emit+0x210/0x218 kernel/printk/printk.c:2275 dev_vprintk_emit+0x278/0x304 drivers/base/core.c:4638 dev_printk_emit+0xd4/0x11c drivers/base/core.c:4649 __netdev_printk+0x2b4/0x39c net/core/dev.c:11503 netdev_info+0xec/0x138 net/core/dev.c:11558 nsim_udp_tunnel_set_port+0x214/0x36c drivers/net/netdevsim/udp_tunnels.c:34 udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline] udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline] __udp_tunnel_nic_device_sync+0x7d8/0xf88 net/ipv4/udp_tunnel_nic.c:289 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:312 [inline] __udp_tunnel_nic_add_port+0x8dc/0xb68 net/ipv4/udp_tunnel_nic.c:531 udp_tunnel_nic_add_port include/net/udp_tunnel.h:336 [inline] udp_tunnel_notify_add_rx_port+0x234/0x384 net/ipv4/udp_tunnel_core.c:130 geneve_socket_create drivers/net/geneve.c:614 [inline] geneve_sock_add+0x3ec/0x778 drivers/net/geneve.c:689 geneve_open+0xc8/0x138 drivers/net/geneve.c:731 __dev_open+0x2f4/0x4e8 net/core/dev.c:1537 __dev_change_flags+0x1ac/0x54c net/core/dev.c:8852 dev_change_flags+0x80/0x154 net/core/dev.c:8923 do_setlink+0xa20/0x3088 net/core/rtnetlink.c:2779 __rtnl_newlink net/core/rtnetlink.c:3450 [inline] rtnl_newlink+0x10d0/0x1404 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9d4/0xd04 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2489 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x60c/0x89c net/netlink/af_netlink.c:1337 netlink_sendmsg+0x6e8/0x9cc net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x2e8/0x3d8 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2071 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 rcu: rcu_preempt kthread starved for 10505 jiffies! g4941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack: 0 pid: 15 ppid: 2 flags:0x00000008 Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xe00/0x1c0c kernel/sched/core.c:6376 schedule+0x11c/0x1c8 kernel/sched/core.c:6459 schedule_timeout+0x180/0x2c8 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x25c/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xc4/0x2a8 kernel/rcu/tree.c:2145 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 0: task:syz-executor188 state:R running task stack: 0 pid: 4086 ppid: 4027 flags:0x00000001 Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:518 .str.2+0xacef29/0xc47a6e