rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10/1:b..l (detected by 0, t=10502 jiffies, g=24969, q=34) task:kworker/u4:1 state:R running task stack:24392 pid: 10 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 preempt_schedule_notrace+0x5b/0xd0 kernel/sched/core.c:6538 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36 rcu_is_watching+0x90/0xc0 kernel/rcu/tree.c:1122 rcu_read_lock include/linux/rcupdate.h:688 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline] batadv_nc_worker+0x132/0xfa0 net/batman-adv/network-coding.c:721 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10493 jiffies! g24969 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:28952 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11136 Comm: syz-executor.3 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0xc/0x12 Code: 56 57 41 50 41 51 41 52 41 53 e8 af 15 00 00 41 5b 41 5a 41 59 41 58 5f 5e 5a 59 c3 66 90 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <3c> 01 75 02 5a c3 56 0f b6 f0 e8 c5 ff ff ff 5e 5a c3 66 90 48 b8 RSP: 0018:ffffc90000fd8d10 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000006 RCX: ffffffff815be6f0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9049b7a8 RBP: ffffffff9049b7a8 R08: 0000000000000000 R09: ffffffff9049b7ab R10: fffffbfff20936f5 R11: 0000000000000000 R12: ffffffff9049b7b0 R13: ffffffff9049b7b8 R14: 1ffff920001fb1ad R15: ffff888089ce02e8 FS: 00007fe2d0b25700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000020d52000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:590 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline] do_raw_spin_unlock+0x171/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irqrestore+0x1e/0x70 kernel/locking/spinlock.c:194 debug_object_deactivate lib/debugobjects.c:757 [inline] debug_object_deactivate+0x264/0x300 lib/debugobjects.c:723 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate kernel/time/hrtimer.c:481 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x3f8/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:vmx_do_interrupt_nmi_irqoff+0x10/0x20 arch/x86/kvm/vmx/vmenter.S:327 Code: 41 5b 41 5a 41 59 41 58 5e 5f 5a 59 58 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83 e4 f0 6a 18 55 9c 6a 10 ff d7 <48> 89 ec 5d c3 cc cc cc cc cc cc cc cc cc cc cc 41 57 48 8d 47 08 RSP: 0018:ffffc90005a3fb48 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff88808df7c080 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff89400bf0 RBP: ffffc90005a3fb48 R08: 0000000080000000 R09: ffff88808df7c2e7 R10: ffffffff811ea28c R11: 0000000000000000 R12: 0000000000000bf0 R13: 0000000089400000 R14: 0000000000000000 R15: ffff88808df7c0b0 handle_interrupt_nmi_irqoff arch/x86/kvm/vmx/vmx.c:6347 [inline] handle_external_interrupt_irqoff arch/x86/kvm/vmx/vmx.c:6377 [inline] vmx_handle_exit_irqoff arch/x86/kvm/vmx/vmx.c:6388 [inline] vmx_handle_exit_irqoff+0x4d2/0x750 arch/x86/kvm/vmx/vmx.c:6380 vcpu_enter_guest+0x2698/0x4410 arch/x86/kvm/x86.c:9701 vcpu_run arch/x86/kvm/x86.c:9819 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10051 kvm_vcpu_ioctl+0x570/0xf30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3779 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe2d35afa39 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe2d0b25188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe2d36b2f60 RCX: 00007fe2d35afa39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007fe2d3609e8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc999fd92f R14: 00007fe2d0b25300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 56 push %rsi 1: 57 push %rdi 2: 41 50 push %r8 4: 41 51 push %r9 6: 41 52 push %r10 8: 41 53 push %r11 a: e8 af 15 00 00 callq 0x15be f: 41 5b pop %r11 11: 41 5a pop %r10 13: 41 59 pop %r9 15: 41 58 pop %r8 17: 5f pop %rdi 18: 5e pop %rsi 19: 5a pop %rdx 1a: 59 pop %rcx 1b: c3 retq 1c: 66 90 xchg %ax,%ax 1e: 52 push %rdx 1f: b8 01 00 00 00 mov $0x1,%eax 24: 31 d2 xor %edx,%edx 26: f0 0f b0 17 lock cmpxchg %dl,(%rdi) * 2a: 3c 01 cmp $0x1,%al <-- trapping instruction 2c: 75 02 jne 0x30 2e: 5a pop %rdx 2f: c3 retq 30: 56 push %rsi 31: 0f b6 f0 movzbl %al,%esi 34: e8 c5 ff ff ff callq 0xfffffffe 39: 5e pop %rsi 3a: 5a pop %rdx 3b: c3 retq 3c: 66 90 xchg %ax,%ax 3e: 48 rex.W 3f: b8 .byte 0xb8