rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=9cd/1/0x4000000000000000 softirq=139939/139940 fqs=4 (detected by 0, t=10502 jiffies, g=236465, q=116 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4574 Comm: kworker/u4:17 Not tainted 5.19.0-rc5-syzkaller-00200-ga471da3100ef #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x1488/0x5660 kernel/locking/lockdep.c:5049 Code: 00 00 48 8d 1c 5b 48 c1 e3 06 48 81 c3 20 cd 67 90 48 8d 7b 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 cb 30 00 00 48 83 7b 40 00 0f 85 e1 f6 ff ff 0f 0b e9 da f6 RSP: 0018:ffffc900003f8b70 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff9067ed60 RCX: ffffffff815d2ee2 RDX: 1ffffffff20cfdb4 RSI: 0000000000000008 RDI: ffffffff9067eda0 RBP: ffff8880750aac3a R08: 0000000000000000 R09: ffffffff9067c907 R10: fffffbfff20cf920 R11: 0000000000000001 R12: ffff8880750aac18 R13: ffff8880750aa140 R14: 0000000000000001 R15: 8cee3dbf4338958c FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f860819d090 CR3: 0000000042093000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] advance_sched+0x53/0x9a0 net/sched/sch_taprio.c:715 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_is_held_type+0xff/0x140 kernel/locking/lockdep.c:5713 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 44 66 8b 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc90003adfb78 EFLAGS: 00000286 RAX: 0000000000000046 RBX: 0000000000000003 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8bd83aa0 R08: 0000000000000000 R09: ffffffff8dbaf6d7 R10: fffffbfff1b75eda R11: 0000000000000001 R12: ffff8880750aa140 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff8880750aabf0 lock_is_held include/linux/lockdep.h:279 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x560/0x780 kernel/locking/lockdep.c:5676 rcu_lock_release include/linux/rcupdate.h:274 [inline] rcu_read_unlock include/linux/rcupdate.h:728 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x86b/0xfa0 net/batman-adv/network-coding.c:719 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 rcu: rcu_preempt kthread starved for 10494 jiffies! g236465 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:28368 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5146 [inline] __schedule+0xa00/0x4b50 kernel/sched/core.c:6458 schedule+0xd2/0x1f0 kernel/sched/core.c:6530 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1999 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2187 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 11766 Comm: kworker/u4:21 Not tainted 5.19.0-rc5-syzkaller-00200-ga471da3100ef #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:518 print_other_cpu_stall kernel/rcu/tree_stall.h:623 [inline] check_cpu_stall kernel/rcu/tree_stall.h:769 [inline] rcu_pending kernel/rcu/tree.c:3977 [inline] rcu_sched_clock_irq+0x2311/0x2370 kernel/rcu/tree.c:2675 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:csd_lock_wait kernel/smp.c:414 [inline] RIP: 0010:smp_call_function_many_cond+0x499/0x1110 kernel/smp.c:988 Code: 01 89 ee e8 69 98 0a 00 85 ed 74 47 48 8b 04 24 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 fc 83 c5 03 e8 09 9c 0a 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 21 0a 00 00 8b 43 08 31 RSP: 0018:ffffc9000407f950 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9b3f740 RCX: 0000000000000000 RDX: ffff888077cc4000 RSI: ffffffff816efb57 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed1017367ee9 R13: 0000000000000001 R14: 0000000000000001 R15: dffffc0000000000 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1154 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1231 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1419 text_poke_flush arch/x86/kernel/alternative.c:1589 [inline] text_poke_flush arch/x86/kernel/alternative.c:1586 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1596 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:811 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:803 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 8d 1c 5b lea (%rbx,%rbx,2),%rbx 6: 48 c1 e3 06 shl $0x6,%rbx a: 48 81 c3 20 cd 67 90 add $0xffffffff9067cd20,%rbx 11: 48 8d 7b 40 lea 0x40(%rbx),%rdi 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 fa mov %rdi,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 2a: 0f 85 cb 30 00 00 jne 0x30fb <-- trapping instruction 30: 48 83 7b 40 00 cmpq $0x0,0x40(%rbx) 35: 0f 85 e1 f6 ff ff jne 0xfffff71c 3b: 0f 0b ud2 3d: e9 .byte 0xe9 3e: da f6 (bad)