rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12480/1:b..l rcu: (detected by 1, t=10503 jiffies, g=52941, q=658 ncpus=2) task:syz.3.1461 state:R running task stack:24520 pid:12480 tgid:12477 ppid:5838 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 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 5f 6c c7 09 65 66 8b 05 2f 50 0c 11 66 85 c0 75 5a bf 01 00 00 00 e8 08 32 0b 00 e8 73 03 43 00 fb 65 8b 05 0b 50 0c 11 <85> c0 75 05 e8 f2 77 ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0000:ffffc9000bc47900 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000200 RCX: 74265e391009db00 RDX: 0000000000000000 RSI: ffffffff8d7e9b20 RDI: ffffffff8bc079e0 RBP: ffffc9000bc47990 R08: ffffffff8f9e1877 R09: 1ffffffff1f3c30e R10: dffffc0000000000 R11: fffffbfff1f3c30f R12: ffffffff896f3c47 R13: ffffc9000e0a1048 R14: dffffc0000000000 R15: 1ffff92001788f20 local_bh_enable include/linux/bottom_half.h:33 [inline] bpf_test_run+0x376/0x7b0 net/bpf/test_run.c:437 bpf_prog_test_run_skb+0xb4e/0x1550 net/bpf/test_run.c:1102 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4673 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6152 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde5f18eec9 RSP: 002b:00007fde5ff86038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fde5f3e5fa0 RCX: 00007fde5f18eec9 RDX: 0000000000000050 RSI: 00002000000002c0 RDI: 000000000000000a RBP: 00007fde5f211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fde5f3e6038 R14: 00007fde5f3e5fa0 R15: 00007ffeb030ef38 rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g52941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=44188 rcu: rcu_preempt kthread starved for 10496 jiffies! g52941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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: 12495 Comm: syz.0.1465 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:check_preemption_disabled+0xa/0x120 lib/smp_processor_id.c:13 Code: c0 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 <65> 48 8b 05 de e4 44 07 48 89 44 24 08 65 8b 05 e6 e4 44 07 65 8b RSP: 0018:ffffc90000007bf0 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000010000 RDX: ffff8880258c9e40 RSI: ffffffff8d7fde67 RDI: ffffffff8bc079e0 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f7c R12: 0000000000000046 R13: ffff8880258c9e40 R14: ffff88802953f300 R15: ffff8880312c7800 FS: 00007f0837fc06c0(0000) GS:ffff888125d0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000150000008d CR3: 0000000077498000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_is_held_type+0x79/0x190 kernel/locking/lockdep.c:5939 lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x160/0xc90 net/sched/sch_taprio.c:932 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_switch+0x102/0x130 kernel/kcov.c:-1 Code: 48 c1 e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 5b <41> 5c 41 5e 41 5f e9 03 ea 8e 09 cc b9 05 00 00 00 48 85 c0 0f 85 RSP: 0018:ffffc9000b5a7730 EFLAGS: 00000246 RAX: 0000000000000020 RBX: ffff88813fe743a0 RCX: 0000000000000005 RDX: ffffffff81c42c60 RSI: ffffffff8e193a50 RDI: 0000000000000005 RBP: 00000084ac1f3178 R08: ffff8880258c9e40 R09: 0000000000000020 R10: 000000000000001f R11: 0000000000000000 R12: ffff88813fe74010 R13: 0000000000000005 R14: 000000000115fec5 R15: 0000000000000390 rb_read_data_buffer+0x110/0x580 kernel/trace/ring_buffer.c:1827 check_buffer+0x28a/0x750 kernel/trace/ring_buffer.c:4394 __rb_reserve_next+0x592/0xdb0 kernel/trace/ring_buffer.c:4493 rb_reserve_next_event kernel/trace/ring_buffer.c:4630 [inline] ring_buffer_lock_reserve+0xbb5/0x1010 kernel/trace/ring_buffer.c:4689 __trace_buffer_lock_reserve kernel/trace/trace.c:1081 [inline] trace_event_buffer_lock_reserve+0x1d0/0x6f0 kernel/trace/trace.c:2799 trace_event_buffer_reserve+0x248/0x340 kernel/trace/trace_events.c:672 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline] trace_event_raw_event_bpf_trace_printk+0x100/0x260 kernel/trace/bpf_trace.h:11 __do_trace_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline] trace_bpf_trace_printk+0x170/0x1d0 kernel/trace/bpf_trace.h:11 ____bpf_trace_printk kernel/trace/bpf_trace.c:379 [inline] bpf_trace_printk+0x11e/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_032721f588c69f2a+0x3e/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x284/0x4b0 kernel/trace/bpf_trace.c:2116 __bpf_trace_sys_enter+0x38/0x60 include/trace/events/syscalls.h:18 __do_trace_sys_enter include/trace/events/syscalls.h:18 [inline] trace_sys_enter+0xb0/0x100 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf9/0x160 kernel/entry/syscall-common.c:53 syscall_enter_from_user_mode_work include/linux/entry-common.h:95 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline] do_syscall_64+0xd3/0xfa0 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f083718eec9 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:00007f0837fc0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f08373e6090 RCX: 00007f083718eec9 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007f0837211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f08373e6128 R14: 00007f08373e6090 R15: 00007ffc382b8dc8