rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6899/1:b..l (detected by 1, t=10503 jiffies, g=84453, q=302) task:kworker/u4:3 state:R running task stack:20984 pid: 6899 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: <TASK> context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31 Code: 41 5e 41 5f 5d c3 48 c7 c7 d2 99 1b 8c eb 0a 48 c7 c7 0a 9a 1b 8c 4c 89 fe e8 b6 fc 68 08 31 db eb d7 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 63 ef ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 RSP: 0018:ffffc90002f37a78 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8162ae1c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de960a8 RBP: ffffc90002f37bd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005e6f58 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888017d567c0 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xcc/0x4f0 kernel/locking/lockdep.c:5594 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 </TASK> rcu: rcu_preempt kthread starved for 10307 jiffies! g84453 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26816 pid: 15 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 </TASK> rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 14971 Comm: syz.2.2896 Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 3e 8c f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 87 87 19 f7 65 8b 05 08 8a c4 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc90003277ba0 EFLAGS: 00000206 RAX: 995d593e90b3fe00 RBX: 1ffff9200064ef78 RCX: ffffffff96868f03 RDX: dffffc0000000000 RSI: ffffffff8a8b2b00 RDI: 0000000000000001 RBP: ffffc90003277c30 R08: ffffffff8186db50 R09: ffffed100367a941 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff9200064ef74 R14: ffffc90003277bc0 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] unlock_task_sighand include/linux/sched/signal.h:718 [inline] do_send_sig_info kernel/signal.c:1295 [inline] group_send_sig_info+0x2ab/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_7ba5217f62dcd359+0x38/0xcb8 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter include/trace/events/syscalls.h:18 [inline] syscall_trace_enter kernel/entry/common.c:77 [inline] __syscall_enter_from_user_work kernel/entry/common.c:96 [inline] syscall_enter_from_user_mode+0x202/0x240 kernel/entry/common.c:114 do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff346490959 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ff34496cb40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007ff3466acf88 RCX: 00007ff346490959 RDX: 00007ff34496cb40 RSI: 00007ff34496cc70 RDI: 0000000000000011 RBP: 00007ff3466acf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff3466acf8c R13: 0000000000000000 R14: 00007ffe618747f0 R15: 00007ffe618748d8 </TASK>