rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1274/1:b..l (detected by 1, t=10502 jiffies, g=37561, q=129) task:kworker/u4:4 state:R running task stack:22456 pid: 1274 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__rcu_read_unlock+0x2/0xd0 kernel/rcu/tree_plugin.h:415 Code: 11 ff 03 8b 03 3d 00 00 00 40 7d 02 5b c3 0f 0b eb fa 89 d9 80 e1 07 80 c1 03 38 c1 7c e3 48 89 df e8 b2 c0 58 00 eb d9 41 57 <41> 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 15 RSP: 0018:ffffc90004947bd0 EFLAGS: 00000293 RAX: ffffffff8991f805 RBX: dffffc0000000000 RCX: ffff888022c90000 RDX: 0000000000000000 RSI: ffffffff8a7a09a0 RDI: ffffffff8a7a0960 RBP: ffff88801e81b740 R08: dffffc0000000000 R09: 1ffffffff203b018 R10: dffffc0000000000 R11: fffffbfff203b019 R12: 00000000000001a2 R13: fffffffffffffe38 R14: ffff88807a464c80 R15: ffff88801e81b750 rcu_read_unlock include/linux/rcupdate.h:772 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x256/0x5c0 net/batman-adv/network-coding.c:723 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10520 jiffies! g37561 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:26960 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9575 Comm: syz.1.1053 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x80 kernel/kcov.c:294 Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 03 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d 64 23 89 7e 65 8b 15 65 23 89 7e 81 e2 00 RSP: 0018:ffffc90000007e68 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 000000a48235c5ac RCX: ffff888025081dc0 RDX: 0000000000010000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 0000000000000000 R08: ffff8880b902a243 R09: 1ffff11017205448 R10: dffffc0000000000 R11: ffffed1017205449 R12: 7fffffffffffffff R13: dffffc0000000000 R14: ffff8880b9027280 R15: 0000000000000003 FS: 00007fa5e1da86c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000060573000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clockevent_state_oneshot_stopped include/linux/clockchips.h:157 [inline] tick_program_event+0x77/0x120 kernel/time/tick-oneshot.c:36 hrtimer_interrupt+0x4de/0x8d0 kernel/time/hrtimer.c:1824 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 4f 9d 8b f7 65 8b 05 70 86 3b 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000c62f380 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: d6f94b74bf4ec900 RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: 0000000000000001 RBP: ffffc9000c62f410 R08: ffffffff901d820f R09: 1ffffffff203b041 R10: dffffc0000000000 R11: fffffbfff203b042 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b902a240 R15: 1ffff920018c5e70 hrtimer_start include/linux/hrtimer.h:420 [inline] stimer_start arch/x86/kvm/hyperv.c:-1 [inline] kvm_hv_process_stimers+0x131a/0x1ac0 arch/x86/kvm/hyperv.c:863 vcpu_enter_guest+0x4793/0x7010 arch/x86/kvm/x86.c:9883 vcpu_run arch/x86/kvm/x86.c:10192 [inline] kvm_arch_vcpu_ioctl_run+0xdea/0x1f40 arch/x86/kvm/x86.c:10432 kvm_vcpu_ioctl+0x8f7/0xc10 virt/kvm/kvm_main.c:3894 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa5e3b4ee59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa5e1da8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa5e3dc7fa0 RCX: 00007fa5e3b4ee59 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007fa5e3be4d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa5e3dc8038 R14: 00007fa5e3dc7fa0 R15: 00007fffbe1645b8