rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15374 rcu: (detected by 1, t=10502 jiffies, g=63769, q=530 ncpus=2) task:syz.2.2723 state:R running task stack:26856 pid:15374 tgid:15368 ppid:5821 task_flags:0x400140 flags:0x00080000 Call Trace: sched_show_task kernel/sched/core.c:7819 [inline] sched_show_task+0x423/0x630 kernel/sched/core.c:7794 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:681 [inline] check_cpu_stall kernel/rcu/tree_stall.h:856 [inline] rcu_pending kernel/rcu/tree.c:3667 [inline] rcu_sched_clock_irq+0x2634/0x31f0 kernel/rcu/tree.c:2704 update_process_times+0x178/0x2d0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x506/0x720 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x64e/0xc40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_raw_spinlock_sequence include/linux/seqlock.h:226 [inline] RIP: 0010:ktime_get_coarse_ts64+0x8b/0x1a0 kernel/time/timekeeping.c:2528 Code: 24 40 48 c7 c7 88 6c c2 9a e8 01 62 ee ff 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 8f 4e 13 00 58 48 85 db 0f 85 f2 00 00 00 b0 53 13 00 44 8b 3d b9 d9 16 19 44 89 fb 31 ff 83 e3 01 89 de RSP: 0018:ffffc9000433f928 EFLAGS: 00000246 RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc90010342000 RDX: 0000000000080000 RSI: ffffffff81ab939b RDI: 0000000000000007 RBP: 1ffff92000867f2d R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888030faaff0 R12: 0000000225c17d03 R13: 7fffffffffffffff R14: ffffc9000433fb7a R15: ffff888030faa4c0 ktime_get_coarse include/linux/timekeeping.h:133 [inline] ktime_get_coarse_ns include/linux/timekeeping.h:139 [inline] ____bpf_ktime_get_coarse_ns kernel/bpf/helpers.c:204 [inline] bpf_ktime_get_coarse_ns+0x8f/0x100 kernel/bpf/helpers.c:202 bpf_prog_ce3dfd7f9330a559+0x1e/0x29 bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:747 [inline] bpf_flow_dissect+0x21b/0x740 net/core/flow_dissector.c:1024 bpf_prog_test_run_flow_dissector+0x438/0x980 net/bpf/test_run.c:1482 bpf_prog_test_run kernel/bpf/syscall.c:4703 [inline] __sys_bpf+0x1035/0x4980 kernel/bpf/syscall.c:6182 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline] __se_sys_bpf kernel/bpf/syscall.c:6272 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6272 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3da318f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3da4022038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3da33e6180 RCX: 00007f3da318f749 RDX: 0000000000000050 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007f3da3213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3da33e6218 R14: 00007f3da33e6180 R15: 00007ffc35ea08f8 rcu: rcu_preempt kthread starved for 10182 jiffies! g63769 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:28064 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: c6 5f 02 c3 cc cc cc cc 0f 1f 00 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 13 49 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000001e668b7 RBX: 0000000000000000 RCX: ffffffff8b7816d9 RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9088b4d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd8bc1156c0 CR3: 000000000e184000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 00000000000000a4 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available