rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7169 rcu: (detected by 1, t=10502 jiffies, g=19585, q=1072 ncpus=2) task:syz.4.223 state:R running task stack:25920 pid:7169 tgid:7168 ppid:5826 task_flags:0x400140 flags:0x00080000 Call Trace: sched_show_task+0x49d/0x630 kernel/sched/core.c:7822 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall+0xf7a/0x1340 kernel/rcu/tree_stall.h:681 check_cpu_stall kernel/rcu/tree_stall.h:856 [inline] rcu_pending kernel/rcu/tree.c:3667 [inline] rcu_sched_clock_irq+0xac1/0x1280 kernel/rcu/tree.c:2704 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x135/0x1c0 kernel/softirq.c:457 Code: 8b e8 bf 63 d8 09 65 66 8b 05 6f 44 1a 11 66 85 c0 75 5a bf 01 00 00 00 e8 f8 9e 0b 00 e8 b3 27 44 00 fb 65 8b 05 4b 44 1a 11 <85> c0 75 05 e8 e2 0b ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc9000e10f8a0 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000200 RCX: 2da312c590112700 RDX: 0000000000000000 RSI: ffffffff8d997e54 RDI: ffffffff8be07960 RBP: ffffc9000e10f930 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee R10: dffffc0000000000 R11: fffffbfff1f445ef R12: ffffffff897c9ab2 R13: ffffc9000e125048 R14: dffffc0000000000 R15: 1ffff92001c21f14 local_bh_enable include/linux/bottom_half.h:33 [inline] bpf_test_run+0x371/0x7d0 net/bpf/test_run.c:426 bpf_prog_test_run_skb+0xd67/0x1d50 net/bpf/test_run.c:1158 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4704 __sys_bpf+0x5ee/0x8a0 kernel/bpf/syscall.c:6226 __do_sys_bpf kernel/bpf/syscall.c:6321 [inline] __se_sys_bpf kernel/bpf/syscall.c:6319 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6319 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f700a18f749 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:00007f700af81038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f700a3e5fa0 RCX: 00007f700a18f749 RDX: 0000000000000050 RSI: 00002000000002c0 RDI: 000000000000000a RBP: 00007f700a213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f700a3e6038 R14: 00007f700a3e5fa0 R15: 00007ffc8e991298 rcu: rcu_preempt kthread starved for 10528 jiffies! g19585 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 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 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: 37a6faac944bdc00 RBX: ffffffff819786ba RCX: 37a6faac944bdc00 RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960 RBP: ffffffff8de07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fa22f70 R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7007ff3f98 CR3: 000000002aad2000 CR4: 00000000003526f0 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 start_kernel+0x3ac/0x400 init/main.c:1208 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147