rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8458/1:b..l rcu: (detected by 1, t=10502 jiffies, g=24037, q=3019 ncpus=2) task:syz.0.670 state:R running task stack:24424 pid:8458 tgid:8455 ppid:5839 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 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:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:222 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 1c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc90003e07870 EFLAGS: 00000246 RAX: ffffffff8a2f0936 RBX: 0000000000000000 RCX: ffff88805f561e00 RDX: ffffc9000c0b1000 RSI: 000000000007ffff RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8a2f0927 R09: 1ffff1100beac3c0 R10: dffffc0000000000 R11: ffffed100beac3c1 R12: ffffc90003e07af0 R13: ffffc90003e07ab0 R14: 1ffff1100beac3c0 R15: dffffc0000000000 bpf_test_timer_continue+0x126/0x380 net/bpf/test_run.c:81 bpf_test_run+0x587/0xa90 net/bpf/test_run.c:438 bpf_prog_test_run_xdp+0x7de/0x1200 net/bpf/test_run.c:1318 bpf_prog_test_run+0x2e4/0x360 kernel/bpf/syscall.c:4427 __sys_bpf+0x4ee/0x8b0 kernel/bpf/syscall.c:5852 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5939 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd90b18e169 RSP: 002b:00007fd90bfb5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fd90b3b5fa0 RCX: 00007fd90b18e169 RDX: 0000000000000050 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007fd90b210a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd90b3b5fa0 R15: 00007ffc41b3f978 rcu: rcu_preempt kthread timer wakeup didn't happen for 5666 jiffies! g24037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=14318 rcu: rcu_preempt kthread starved for 5667 jiffies! g24037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 8f 18 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a080d8 EFLAGS: 00000246 RAX: ffffffff816ce994 RBX: dffffc0000000000 RCX: ffff88801cefda00 RDX: 0000000000000100 RSI: ffffffff8e6499b7 RDI: ffffffff8ca1b5a0 RBP: ffffc90000a081b0 R08: ffffffff905fe577 R09: 1ffffffff20bfcae R10: dffffc0000000000 R11: fffffbfff20bfcaf R12: ffffffff93686020 R13: 1ffff92000141020 R14: 0000000000000003 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055894900bd88 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] kvm_wait+0x2c9/0x330 arch/x86/kernel/kvm.c:1063 pv_wait arch/x86/include/asm/paravirt.h:584 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x8d4/0xdc0 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:572 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x276/0x370 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] __dev_xmit_skb net/core/dev.c:4054 [inline] __dev_queue_xmit+0xe04/0x3f60 net/core/dev.c:4595 dev_queue_xmit include/linux/netdevice.h:3350 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0x125c/0x1750 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xb58/0x1560 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x380/0x680 net/ipv6/addrconf.c:4038 call_timer_fn+0x189/0x650 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x66e/0x8e0 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 8f 18 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197dc0 EFLAGS: 000002c2 RAX: c7fd0ede63bb0e00 RBX: ffffffff8197272e RCX: ffffffff8c2fa93c RDX: 0000000000000001 RSI: ffffffff8e6499b7 RDI: ffffffff8ca1b5a0 RBP: ffffc90000197f20 R08: ffff8880b8732b5b R09: 1ffff110170e656b R10: dffffc0000000000 R11: ffffed10170e656c R12: 1ffff92000032fd2 R13: 1ffff110039dfb40 R14: 0000000000000001 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x22e/0x5d0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0xfe/0x100 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147