rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6579 rcu: (detected by 0, t=10502 jiffies, g=12389, q=1102 ncpus=2) task:syz.4.181 state:R running task stack:25000 pid:6579 tgid:6576 ppid:5829 task_flags:0x400140 flags:0x00080001 Call Trace: sched_show_task+0x49d/0x630 kernel/sched/core.c:7901 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall+0xf78/0x1340 kernel/rcu/tree_stall.h:681 check_cpu_stall kernel/rcu/tree_stall.h:857 [inline] rcu_pending kernel/rcu/tree.c:3671 [inline] rcu_sched_clock_irq+0xa47/0x11b0 kernel/rcu/tree.c:2706 update_process_times+0x235/0x2d0 kernel/time/timer.c:2473 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x506/0xd40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45d/0xa90 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:702 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:751 Code: e8 6b 4e 12 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 5d da 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 3c 12 7b 00 48 c7 c3 d8 34 81 91 49 03 1e 48 89 RSP: 0018:ffffc9000fa6f650 EFLAGS: 00000246 RAX: 1ffffffff19b4ba2 RBX: 0000000000000000 RCX: 98bf5cc8f1b29800 RDX: ffff88801caf98c0 RSI: ffffffff8b1dd040 RDI: ffffffff8b1dd000 RBP: 0000000000000800 R08: 00000000ffffffff R09: 0000000000000000 R10: ffff8881d3120280 R11: ffffffff81a98770 R12: 00000000000000f0 R13: ffff8881d3120280 R14: ffffffff8cda5d10 R15: dffffc0000000000 trace_kmem_cache_alloc+0x1f/0xc0 include/trace/events/kmem.h:12 kmem_cache_alloc_noprof+0x1d8/0x6b0 mm/slub.c:5255 skb_clone+0x212/0x3a0 net/core/skbuff.c:2050 ____bpf_clone_redirect net/core/filter.c:2463 [inline] bpf_clone_redirect+0xad/0x3d0 net/core/filter.c:2448 bpf_prog_85e106f90f6bc4e0+0x62/0x6b 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_test_run+0x318/0x7b0 net/bpf/test_run.c:434 bpf_prog_test_run_skb+0xb4e/0x1550 net/bpf/test_run.c:1102 bpf_prog_test_run+0x2cd/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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe56667eec9 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:00007fe5648de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fe5668d5fa0 RCX: 00007fe56667eec9 RDX: 0000000000000050 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007fe566701f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe5668d6038 R14: 00007fe5668d5fa0 R15: 00007ffe95535e28 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g12389 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=9457 rcu: rcu_preempt kthread starved for 10502 jiffies! g12389 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0