rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4475/1:b..l P5470/2:b..l rcu: (detected by 1, t=10503 jiffies, g=9605, q=895 ncpus=2) task:kworker/0:5 state:R running task stack:25000 pid:5470 tgid:5470 ppid:2 flags:0x00004000 Workqueue: mld mld_ifc_work Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1a0b/0x4be0 kernel/sched/core.c:6746 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 __local_bh_enable_ip+0x179/0x1f0 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:851 [inline] __dev_queue_xmit+0x1622/0x3b40 net/core/dev.c:4368 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xfed/0x1650 net/ipv6/ip6_output.c:137 __ip6_finish_output net/ipv6/ip6_output.c:211 [inline] ip6_finish_output+0x4de/0x910 net/ipv6/ip6_output.c:222 dst_output include/net/dst.h:450 [inline] NF_HOOK+0x17a/0x720 include/linux/netfilter.h:314 mld_sendpack+0x70a/0xbf0 net/ipv6/mcast.c:1818 mld_send_cr net/ipv6/mcast.c:2119 [inline] mld_ifc_work+0x7d6/0xd90 net/ipv6/mcast.c:2650 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17b0 kernel/workqueue.c:3335 worker_thread+0xa60/0xff0 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:udevd state:R running task stack:23592 pid:4475 tgid:4475 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1a0b/0x4be0 kernel/sched/core.c:6746 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108 sock_def_readable+0x1fa/0x470 net/core/sock.c:3354 __netlink_sendskb net/netlink/af_netlink.c:1282 [inline] netlink_sendskb+0x9e/0x140 net/netlink/af_netlink.c:1288 netlink_unicast+0x39d/0x980 net/netlink/af_netlink.c:1376 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x88/0x170 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f692e124a4b RSP: 002b:00007fff8d33e8c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000055b34f170df0 RCX: 00007f692e124a4b RDX: 0000000000000000 RSI: 00007fff8d33e8d8 RDI: 0000000000000004 RBP: 000055b34f192fd0 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000000b2 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10564 jiffies! g9605 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:26536 pid:15 tgid:15 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1a0b/0x4be0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1360 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5626 Comm: syz-executor.2 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:ct_state include/linux/context_tracking_state.h:137 [inline] RIP: 0010:syscall_exit_to_user_mode_prepare kernel/entry/common.c:185 [inline] RIP: 0010:__syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] RIP: 0010:syscall_exit_to_user_mode+0x337/0x360 kernel/entry/common.c:218 Code: fa bf 01 00 00 00 e8 c8 06 40 f6 e8 43 11 00 00 89 c0 48 8b 04 c5 a0 f9 67 8d 8b a8 88 7c 03 00 bf 01 00 00 00 e8 49 08 40 f6 <65> 8b 05 9a da df 74 85 c0 75 05 e8 59 b9 dc f5 40 f6 c5 03 0f 84 RSP: 0018:ffffc90005ab7ee8 EFLAGS: 00000297 RAX: 0000000080000001 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bbae020 RDI: 0000000000000001 RBP: 000000000211152c R08: ffffffff81330eae R09: 1ffff92000b56f8a R10: dffffc0000000000 R11: fffff52000b56f8b R12: ffff888067ea9e00 R13: 0000000000000000 R14: ffffc90005ab7f58 R15: ffffffffffffffff FS: 00007fcc1e1c56c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcc1e1c4f00 CR3: 0000000070500000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_syscall_64+0x94/0x170 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fcc1d47de69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcc1e1c50c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fcc1d5abf80 RCX: 00007fcc1d47de69 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fcc1d4ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fcc1d5abf80 R15: 00007ffd058aa448 sched: RT throttling activated