rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3576/1:b..l (detected by 1, t=10503 jiffies, g=5981, q=21 ncpus=2) task:syz-executor524 state:R running task stack:24984 pid:3576 ppid:3570 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:packet_notifier+0x12c/0xa30 net/packet/af_packet.c:4151 Code: c2 80 15 f0 8b e8 74 04 05 f8 48 81 c3 b8 03 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 c7 4b 7c f8 4c 8b 3b <4d> 85 ff 0f 84 3b 08 00 00 49 83 c7 98 0f 84 31 08 00 00 48 8b 44 RSP: 0018:ffffc90003c3f7f8 EFLAGS: 00000246 RAX: 1ffff1100e685b0f RBX: ffff88807342d878 RCX: ffff8880767d1dc0 RDX: 0000000000000000 RSI: ffffffff8b3cf3a0 RDI: ffffffff8b3cf360 RBP: 0000000000000001 R08: ffffffff8965a382 R09: fffffbfff2091c45 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000005 R15: 0000000000000000 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:1970 [inline] call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers+0x145/0x1b0 net/core/dev.c:2022 register_netdevice+0x12f2/0x1720 net/core/dev.c:10126 register_netdev+0x37/0x50 net/core/dev.c:10219 ip6gre_init_net+0x211/0x2e0 net/ipv6/ip6_gre.c:1644 ops_init+0x356/0x600 net/core/net_namespace.c:135 setup_net+0x4b5/0xb90 net/core/net_namespace.c:332 copy_net_ns+0x395/0x5d0 net/core/net_namespace.c:478 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f22996822f7 RSP: 002b:00007ffe03626f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007ffe03626f68 RCX: 00007f22996822f7 RDX: 00007f2299680e79 RSI: 00007ffe03626fe0 RDI: 0000000040000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000555555d7d370 R13: 0000000000000003 R14: 0000000000000003 R15: 00007ffe03626fa0 rcu: rcu_preempt kthread starved for 10537 jiffies! g5981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27032 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1674 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1873 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 3600 Comm: syz-executor524 Not tainted 6.1.65-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:xsave_to_user_sigframe arch/x86/kernel/fpu/xstate.h:279 [inline] RIP: 0010:copy_fpregs_to_sigframe arch/x86/kernel/fpu/signal.c:162 [inline] RIP: 0010:copy_fpstate_to_sigframe+0x51e/0xda0 arch/x86/kernel/fpu/signal.c:231 Code: 57 00 4c 89 e3 48 c1 eb 20 4c 89 ff 4c 89 e6 31 d2 e8 56 46 00 00 0f 01 cb 4c 8b 7c 24 20 4c 89 ff 44 89 e0 89 da 48 0f ae 27 <31> c0 89 c3 0f 01 ca 48 8b 44 24 30 42 0f b6 04 28 84 c0 0f 85 c9 RSP: 0018:ffffc90003cff980 EFLAGS: 00040286 RAX: 0000000000000007 RBX: 0000000000000000 RCX: ffff888077343b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffe03626b40 RBP: ffffc90003cffb50 R08: ffffffff8132fe70 R09: ffffed100ee68771 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000007 R13: dffffc0000000000 R14: ffff888077343b80 R15: 00007ffe03626b40 FS: 0000555555d7d3c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000140 CR3: 0000000029cfc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: get_sigframe+0x378/0x4b0 arch/x86/kernel/signal.c:297 __setup_rt_frame arch/x86/kernel/signal.c:472 [inline] setup_rt_frame arch/x86/kernel/signal.c:784 [inline] handle_signal arch/x86/kernel/signal.c:828 [inline] arch_do_signal_or_restart+0x4ef/0x1a10 arch/x86/kernel/signal.c:873 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2299680e79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 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:00007ffe03626f38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f2299680e79 RDX: 0000000020000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000555555d7d370 R13: 0000000000000000 R14: 00007ffe03626fb0 R15: 00007ffe03626fa0 sched: RT throttling activated