rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=f034/1/0x4000000000000000 softirq=68588/68588 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6624/1:b..l rcu: (detected by 0, t=10502 jiffies, g=86625, q=175 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17676 Comm: syz.4.3363 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__lock_acquire+0xec7/0x2100 Code: 31 d9 44 01 f0 41 29 ce 89 ca c1 c2 06 44 31 f2 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da <89> dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 RSP: 0018:ffffc90000a18a10 EFLAGS: 00000092 RAX: 00000000001048a1 RBX: 00000000050645da RCX: 000000001058aa7d RDX: 00000000fae9315e RSI: 00000000ef968c96 RDI: dffffc0000000000 RBP: ffff888068620af0 R08: ffffffff942c3847 R09: 1ffffffff2858708 R10: dffffc0000000000 R11: fffffbfff2858709 R12: ffff888068620000 R13: ffff888068620000 R14: 0000000000004022 R15: 0000000000000001 FS: 00007f63fd16a6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002001f000 CR3: 0000000034622000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1738 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1864 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5251 Code: c9 50 e8 79 09 0c 00 48 83 c4 08 4c 89 f7 e8 fd 39 00 00 e9 de 04 00 00 4c 89 f7 e8 e0 81 61 0a e8 cb 66 38 00 fb 48 8b 5d c0 <48> 8d bb 08 16 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc90004a87588 EFLAGS: 00000282 RAX: 1dde09cff66af600 RBX: ffff888068620000 RCX: ffffffff9a3ca903 RDX: dffffc0000000000 RSI: ffffffff8c0aa680 RDI: ffffffff8c5fac60 RBP: ffffc90004a875d0 R08: ffffffff901a1777 R09: 1ffffffff20342ee R10: dffffc0000000000 R11: fffffbfff20342ef R12: 1ffff110170e7eb6 R13: dffffc0000000000 R14: ffff8880b863e780 R15: ffff8880b873f5b0 context_switch kernel/sched/core.c:5380 [inline] __schedule+0x18c4/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 rdmsr_safe_on_cpu+0x16c/0x310 arch/x86/lib/msr-smp.c:181 msr_read+0x15d/0x260 arch/x86/kernel/msr.c:66 vfs_read+0x1f8/0xb40 fs/read_write.c:563 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f63fc38cda9 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:00007f63fd16a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f63fc5a5fa0 RCX: 00007f63fc38cda9 RDX: 0000000000018ff8 RSI: 0000000020019680 RDI: 0000000000000004 RBP: 00007f63fc40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f63fc5a5fa0 R15: 00007ffd08d4b3e8 task:kworker/u8:12 state:R running task stack:20280 pid:6624 tgid:6624 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7086 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:__rcu_read_unlock+0x5/0x110 kernel/rcu/tree_plugin.h:431 Code: e1 07 80 c1 03 38 c1 7c aa 4c 89 ff e8 94 78 7d 00 eb a0 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df 65 4c 8b RSP: 0018:ffffc90003037a38 EFLAGS: 00000246 RAX: 5a3b27cafee85a00 RBX: ffff8880607a8d80 RCX: ffffc90003037903 RDX: 0000000000000002 RSI: ffffffff8c0ab8e0 RDI: ffffffff8c5fac60 RBP: ffff8880332c8180 R08: ffffffff901a1777 R09: 1ffffffff20342ee R10: dffffc0000000000 R11: fffffbfff20342ef R12: ffff8880607a8d80 R13: 1ffff1100c0f5314 R14: ffff88814c6ab318 R15: ffffffff8bb95dd0 rcu_read_unlock include/linux/rcupdate.h:882 [inline] batadv_nc_process_nc_paths+0x2f5/0x3a0 net/batman-adv/network-coding.c:699 batadv_nc_worker+0x52c/0x610 net/batman-adv/network-coding.c:735 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10502 jiffies! g86625 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:25656 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 c0 d4 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d a5 89 7b 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e607ca8 EFLAGS: 00000246 RAX: ffffffff8e696580 RBX: ffff888144e90064 RCX: 00000000017e8191 RDX: 0000000000000001 RSI: ffff888144e90000 RDI: ffff888144e90064 RBP: 000000000003a8f8 R08: ffff8880b863795b R09: 1ffff110170c6f2b R10: dffffc0000000000 R11: ffffffff8bedab50 R12: ffff888147687000 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f11d240 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c37608d CR3: 0000000034622000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 rest_init+0x2dc/0x300 init/main.c:743 start_kernel+0x484/0x510 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x147